Fixes #9635

Fixes #10221

Fixes #10424

Also fixes the problem that notifications were never removed on the server side

Fixes #2114, fixes #10481

Fixes #7833

Adds the ability to set the content mode for the description of a menu item that is part of a menu bar.
This functionality was already available for every AbstractComponent but missing for the menu items of menu bars.
If no content mode is specified it defaults to the PREFORMATED content mode.

Fixes #10304

Adds v-select-option-selected class to the selected
group items in CheckboxGroup and RadiobuttonGroup
Fixes #3387

Fixes `DateField blur event fires when focus gets to the "calendar button"` #1008

* Fix missing v-disabled for RadioButtonGroup
* Fix missing v-disabled for CheckBoxGroup

Resolves #9258

* Rename HierarchicalDataCommunicator#getMapper to getHierarchyMapper

* Make rpc field in Notification private

* Change DropIndexCalculator.ALWAYS_DROP_TO_END to a generic static method

* Move EditorImpl#editRow documentation to the interface level

* Correct GridDragEndEvent, GridDragStartEvent constructor javadocs

* Revert SharedState.registeredEventListeners to a Set

* Rename GridDropTarget dropAllowedOnSortedGridRows

* Rename ColumnState.contentMode to tooltipContentMode

* Accessibility for MenuBar (#3922)
* TabIndex handling fix and an indexing tweak
* Make disabled MenuItems selectable for accessibility (#3922)

- It should be possible to navigate to a disabled MenuItem, even if
triggering the related command is disabled

* Refactor primary style name and aria attribute handling to own method

* Add new drop mode ON_GRID for GridDropTarget

Also adds a way to not accept drops on rows when the user has sorted the grid.
This way the bad UX can be avoided for showing the drop indicator for the wrong place when the grid has been sorted.
This has not been made default behavior to GridDropTarget since it would change behavior compared to 8.1.
Instead if is triggerable via API in GridDropTarget.

* Refactor sorted grid drop logic to server side

* Block setDropMode calls

Blocking setDropMode set values if the grid has been sorted and drop on
sorted rows is not allowed. The value is used once the grid is not sorted
anymore or the drops are allowed on sorted rows.

From VDateField and VWindow

Based on vaadin/flow#2834

Make focus circulate in modal dialog to improve accessibility

Because VConsole is deprecated and it recommends using Logger instead

In some places, getWidget() is called many times, and I believe this can
have a litte performance improvement, since in some cases
super.getWidget() is called more than once.

Fixes #10214

* add Grid#Column#get/setAssistiveCaption

* fix test and update doc

* move testGridAssistiveCaption to GridTest

* delete test file

* delete test file

* Delete GridAssistiveCaptionTest.java

* Create GridAssistiveCaptionTest

* Create GridAssistiveCaption

* Rename GridAssistiveCaption to GridAssistiveCaption.java

* Rename GridAssistiveCaptionTest to GridAssistiveCaptionTest.java

* Reformat using eclipse

Also improve naming by replacing one-letter variable names.

Also use "event" as the name for events

* Variable names to conform to naming convention.

* Use static constants where it makes sense

* adds simple fix for missing label text in grid select checkboxes

* updated comment and wording

* Unlock panel caption div hacking

Fixes #10119

* Javadoc formatting fix

* AbstractDateField.formatDate to be abstract

Remove invalidDateString paramter, as it can be deduced

* Fix test

* Remove AbstractDateField.getResolutionVariable

VAbstractTextualDate: rename updateDateVariables() to updateBufferedResolutions()

* Revert to use fixed value of MONDAY.

* release notes

* updateAndSendBufferedValues()

* Missed call to updateAndSendBufferedValues();

* release note

* Fix typos

* Fix

* Check whether className is of type string

* Move string type checker method to widget util

* Fix formatting of WidgetUtil

* Break svg into lines

* add role="row" and role="gridcell"

* optimize code and add additional rows for the header

* add simple test

* improve code and add rowgroup

* add debug log

* add more log to test

* remove debug test info and add role before appending to tr

* wording - change contains to contain

* create enum for magic strings, change comments and method signature

* rename enum to be singular and rename param roleName to role

* update javadoc, rename and make enum public

* Use .toLowerCase and .toUpperCase(Locale.ROOT)

* Spaces

* add spaces after if(

* Fix HTML tags inside code in javadoc

* only modify <table> and <tr>

* Fix javadoc