Fixes #10146
Fixes #10543

Fixes #9922

Fixes #10232

Fixes #10461

Fixes #10454

Fixes #10284

Fixes #10540

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

Fixes #2114, fixes #10481

* Disallow some `null` arguments
* Return an unmodifiable map from getDateStyles(). This helps the
developer understand that changes to the returned map are
not automatically applied to the component.
* Remove redundant `@link` markup from `@see` in the javadocs.

* Fix wrong frontend URL in docs.

* Update HtmlImport.java

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 #10476

Fixes #10434

Fixes #10304

Binder.setReadonly will ignore bindings with null setter
or property without an accessible setter when changing
field read only flag.

Fixes #10252

Fixes #9663

Also update declarative writing to use true instead of "" for empty
attributes because of changed defaults in JSoup. For v7, the tests are
updated instead of touching the implementations.

* Changed retrieval of names of nested properties (#10159)

The getName() function in NestedBeanPropertyDefinition will return only the top level name, which causes problems when adding a nested property that has the same name as a non-nested (e.g "value" & "sub.value")

This change should fix this behaviour by changing the return value of "getName()" of NestedBeanPropertyDefinition and introducing a function "getTopLevelName()" that only returns the last part of the full name for where it's needed

This patch also adds ValueChangeEvent as a parameter to field value change method in Binder.

Deprecate com.vaadin.ui.components.grid.DescriptionGenerator
and subclass it from the new DescriptionGenerator.

* 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

This commit extracts the private nested class AbstractBeanPropertyDefinition from BeanPropertySet to a public class of package com.vaadin.data.

Additionally, the nested protected class PropertyFilterDefinition is extracted from NestedBeanPropertyDefinition to a public class in package com.vaadin.data.

The old name GridDragger gave an impression that you're dragging the whole grid instead of rows.

This pathc also switches GridDragger to by default not allow drops on rows when the
grid has been sorted.

* Added Griddragger.

* Refactored the GridDragger to match FW style

Unit tests, Test UI and documentation to come next.

* Change DropMode to BETWEEN and add Test UIs

* Simplify GridDragger API

* Fixes and unit tests for GridDragger

Fixed issues regarding drop index calculation when sourche and target grid is the same.
When the ListDataProvider is not internally using List, always drops to the end.
Updates the old data provider instead of creating a new one to preserve filters&sorting.

* 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.

Fixes #10195

Fixes #9210

UIDL might contain sensitive information that we should prevent from
being stored anywhere.

Fixes #10292