Column widths shouldn't be calculated between the clearing of cache and
re-populating it, but be delayed until the cache has some content again.
The calculations should only be triggered immediately if no rows are
expected.

Fixes #9996

* Fix an issue with frozen column count and unhiding.

Unhiding logic should take into account that there can be hidden frozen
columns that are not the column currently getting shown.

There is no need to reset the sidebar for every column that is set
hidable within the same roundtrip. Because no other layouting depends on
the sidebar contents, we can safely delay the reset until all columns
have got their hidabiity status updated. As a bonus point, when the
reset itself is delayed, the headers have time to get populated and the
sidebar button's height can be determined immediately at attach. The
reset ensures that attach is called every time a column's hidability is
changed.

Fixes #11892

* Rewrote debouncing of onResize 

Fixes https://github.com/vaadin/framework/issues/11892

* Fixing typo in variable name

* Removed outdated spacer height update from removal process.

Fixes #11856

If first attempt at scrolling doesn't succeed it's unlikely that
continuing to wait is going to make any difference. Cache should be
populated before triggering any actions that depend on the row being
visible, otherwise it should be enough to trust that scrollToRow
actually scrolls to row and once scrolling is done the row is as much in
view as it's going to get. This way we don't get into a situation where
Editor never opens because it's still waiting for that one last pixel
that can't be achieved thanks to browser zoom causing rounding errors.

Continues on #11672

- If the Grid has frozen columns zooming can cause the regular column
cells to be ever so slightly out of sync with their corresponding rows.
This difference is not noticeable to naked eye but is big enough that
it's possible to hover over the row instead of the cell, which causes an
assertion error and a big ugly error popup. Switching to logging retains
the information delivered by the assertion error for developer purposes
but makes the end user experience smoother.
- Can be tested manually with GridColumnFrozenColumn test UI.

Fixes #11198

- The new top row logical index should always be within the logical
range and high enough up to avoid leaving a gap if possible.
- Added regression testing for using the different scroll destination
types for scrolling to the top and to the bottom by index.

Fixes #11732

* Catch and handle IllegalStateException

Fixes https://github.com/vaadin/framework/issues/11730

* Renaming variables

- Initial implementation erroneously assumed that
ScrollDestination.START would only be used for scrolling up and
ScrollDestination.END for scrolling down. That's obviously not what they
are for, otherwise everyone would be using ScrollDestination.ANY.
- Moved actual scrolling to within the helper method that originally
only calculated the new scroll position. Parent method became too long
otherwise.

Fixes #11706

Updated row and spacer handling for Escalator.

Main changes:
- Spacers are only maintained and checked for rows that have DOM
representation, and not at all if there is no details generator. This
gives notable performance improvements to some particularly large Grids
- Escalator no longer tries to trim away any rows that don't fit within
the viewport just because a details row gets opened in Grid. This leads
to some increase in simultaneous DOM elements, but simplifies the logic
considerably. For example opening or closing details rows doesn't
require checking the overall content validity beyond the details row
itself anymore, but some repositioning at most. There are also no longer
any orphaned spacers without corresponding DOM rows.
- Spacers are better integrated into the overall position calculations.
- Some public methods that are no longer used by Escalator or have
changed functionality or order of operations. Any extending classes that
tap into row, spacer, or scroll position handling are likely to need
reworking after this update.
- Auto-detecting row height is delayed until Escalator is both attached
and displayed.

* Update the since tag

* Apply offset to column index depending on presense of selection column

After testing this manually I noticed that offset correction needs to be negative

* Add the testing UI

- Escalator should notify when an existing details row is moved to a new
index.
- Grid and DetailsManagerConnector should update their internal indexing
when details manager index changes in Escalator.

* Adding "v-grid-editor-selected" stylename in editor cell wrapper element when Grid is opened on selected row.

1) recalculate the offset, as ChromeDriver starts to follow the standard;
2) update screenshots;
3) correct the `click()` call with using coordinates, related to 1)
4) `sendkey()` with using key.modifier adjustment
5) add sleep 
6) workaround for mastery failures

* Recalculate the column widths before the first row is added

Fixes #11607

* Fix grid column reordering

Fix grid column reordering when there are hidden columns and footerRow.join

* Add test

Fixes #11558

Fixes #11557

* Improvements to updating spacer indexes.

- When details rows are moved down, indexes need to be updated from
bottom up.

Fixes #11352

- When rows are added, details row heights need to be taken into account
in positioning.

Fixes #11348

* Fix to use correct spacer index and existing helper method.

Fixes #11325

* Fix for setting default row height for a Grid with details row(s) open.

- Details row(s) should be taken into account when the rows are
re-positioned after getting new heights.

Fixes #11325

- Multiple headers shouldn't stack behind each other.
- Body rows shouldn't get stuck to default row height.
- Compatibility version's hidable row selector shouldn't try to
calculate row heights based on rows that haven't been added to DOM yet.

Fixes #7674

- More lightweight, and fixes things for any custom implementations of
Escalator as well.

Fixes #11044

Ensure that HeaderRow is not null in Grid

Fixes #10485

Fixes #9731

Fixes #10931

Fixes #10699

Fixes #9477

Fixes #7527

* @since 8.3.2

Fixes #10429

* implement focus handing in RadioButtonGroup, fixes #10429

* Merge branch 'master' of https://github.com/vaadin/framework into radiobuttongroup-focus

* merge

* Merge branch 'master' of https://github.com/vaadin/framework into radiobuttongroup-focus

* fix initial focus handling also on CheckBoxGroup and add tests

* add license headers

* Merge branch 'master' of https://github.com/vaadin/framework into radiobuttongroup-focus

* changed client to use lambdas and refactored focus testing to parent class

* made FocusTest abstract

* Merge branch 'master' of https://github.com/vaadin/framework into radiobuttongroup-focus

* don't allow focusing on disabled items & refactor focusing first item

Fixes #10232