* TapGestureRecognizer no longer adds the pointer after it resets.

* Adds an assertion to make sure TapGestureRecognizer.startTrackingPointer is never called when _down is null

This PR rewrites MouseTracker's lifecycle, so that mouse callbacks are all triggered in post frame, instead of the current one where some are triggered during the build phase. This PR also changes the onExit callback to MouseRegion, RenderMouseRegion, and MouseTrackerAnnotation, so that it is no longer triggered on dispose.

* Update project.pbxproj files to say Flutter rather than Chromium

Also, the templates now have an empty organization so that we don't cause people to give their apps a Flutter copyright.

* Update the copyright notice checker to require a standard notice on all files

* Update copyrights on Dart files. (This was a mechanical commit.)

* Fix weird license headers on Dart files that deviate from our conventions; relicense Shrine.

Some were already marked "The Flutter Authors", not clear why. Their
dates have been normalized. Some were missing the blank line after the
license. Some were randomly different in trivial ways for no apparent
reason (e.g. missing the trailing period).

* Clean up the copyrights in non-Dart files. (Manual edits.)

Also, make sure templates don't have copyrights.

* Fix some more ORGANIZATIONNAMEs

Drag from the right is no more
Longpress is now only 100ms instead of 500
Added optional duration field to longpressgesturerecognizer
Added controller field to material scrollbar api
Haptic feedback only triggers when scrollbar is fully expanded
Added haptic feedback when releasing the scrollbar after dragging it

* Revert "Revert "Rewrite MouseTracker's tracking and notifying algorithm (#42031)" (#42478)"

This reverts commit eede7929.

* Fix tests

* Redesigns the algorithm with which MouseTracker keeps track of states and dispatches events. 

* Make sendMouseNotifications private

Add more web tests;use blacklist instead of whitelist

* Extract pointerData and _equalToEventsOnCriticalFields for simplicity

* Extracts the logic of TapGestureRecognizer into an abstract class BaseTapGestureRecognizer
* Fixes ModalBarrier unable to dismiss when competing

* add missing trailing commas

* add more missing trailing commas

* add more and more missing trailing commas

* MouseRegion documentation claimed that onEnter and onExit
  would track entry and exit regardless of whether the pointer was
  down or up
* It did such, but when grabbing the value of `event.down` from
  the passed event, the value was always `false`
* PointerEnterEvent and PointerExitEvent were overriding the value
  passed from PointerEvent in constructors, even if the value was true
  e.g. in invocations of .fromMouseEvent((PointerMoveEvent...))
* This change now passes the value along to PointerEnter/ExitEvents
  while providing it a default of false, and updates documentation

Fixes #40637

This fixes the mouse hover code to not schedule frames with every mouse move.

Before this, it would schedule a post frame callback, and then schedule a frame immediately, even if there was nothing that needed to be updated. Now it will schedule checks for mouse position updates synchronously, unless there's a new annotation, and skip scheduling a new frame in all cases. It has to be async in the case of a new annotation (i.e. a new MouseRegion is added), since when the annotation is added, it hasn't yet painted, and it can't hit test against the new layer until after the paint, so in that case it schedules a post frame callback, but since it's already building a frame when it does that, it doesn't need to schedule a frame.

The code also used to do mouse position checks for all mice if only one mouse changed position. I fixed this part too, so that it will only check position for the mouse that changed.

Add "OneSequenceRecognizer.resolvePointer". Fix DragGestureRecognizer crash on multiple pointers (#39017)

* Add drag tests

* Add resolvePointer

* Correct monodrag implementation

* Fix some addTearDown

This reverts commit 572f349f.

- A refactor that moves the semantics declaration from detectors to recognizers to allow custom recognizers to respond to semantic gectures.
- Renames all handlers related to semantics from Gesture* to Semantics*.

This PR solves two problems: currently, the onExit is called for a mouse pointer the moment the removal message is received, except that by the time it actually calls it, there is no _lastEvent for it in the mouse tracker (it's already been removed), resulting in an event being passed to the onExit that contains nulls for the position. Also, removePointer events don't actually get created with a position, although they easily could be, so that even the the _lastEvent in the mouse tracker were still populated, it would still give a null position and delta.

This PR adds support for the position and delta in a PointerRemovedEvent, and populates them. In addition, when a remove event is received, it doesn't actually remove the pointer until the mouse position check that gets scheduled actually happens.

Updates documentation and non-public API to use American spellings for
consistency with the rest of the codebase.

No changes to behaviour... other than how it's spelt.

Corects a bnuch of typeos throuhgout teh Fluter codebsae.

Made use of the `misspell` tool:
https://github.com/client9/misspell

* Revert "Revert "Redo: Add buttons to gestures (#31819)" (#31912)"

This reverts commit 60a1b2b9.

This reverts commit 18ca3754.

This changes Listener to trigger enter/move/exit in all Listeners below the pointer, not just the leaf region (the first region hit). This is because we need to allow listeners to be nested so that, say, a widget that handles changing color on hover, but also is wrapped in a Tooltip (that handles hover) can trigger both actions, not just one.

To that end, I added a findAll to Layer, similar to the existing find method that was previously used. It returns an iterator over annotated layers which match the given data type.

Since the findAll is implemented as returning an Iterable (and is sync*), I re-implemented the find routines as just returning the first result from findAll, since that should be just as efficient, and would then prevent duplication in the implementation.

* Revert "Revert "Remove pressure customization from some pointer events (#30414)" (#30873)"

This reverts commit f34c2ef0.

* Revert pressure removal of PointerUpEvent

* Replace PR with an issue

* Add tests for fromMouseEvent