Document and clean up events in all the things

* Document them consistently between secetions Inheritance and
  Static Properties under their own (new) section Events.
* Removed any quotes or brackets around the event name in existing
  @emit annotations
  Search: @emit.*['"{}(){}]
* For every call to this.emit() anywhere, added @emits.
* Fixed all warnings for references to undefined events
  (introduced as a result of the previous point).
  Event handler parameter documented based on the emit() call
  and actual handlers using the event. Usually the latter is
  more elaborate.
* Extend coverage of jQuery as needed
  (copied from mwcore/maintenance/jsduck/external.js
  written by me, hereby implicitly and explicitly released under MIT).

Specifics
* ve.ce.Surface#onContentChange: Fixed type of range from Object to ve.Range.
* ve.ce.SurfaceObserver#poll: Fix syntax for code from {} to `backticks`.
* ve.ui.Toolbar#onContextChange: Doesn't actually emit "clearState" event.
  Removed #onClearState in Tool, ButtonTool and DropdownTool.

Bug: 45872
Change-Id: Id879aa769b2c72d86a0322e75dddeb868211ce28
Merge "Document and clean up events in all the things"