Fixes scrolling by dragging a selection when the field is in a Scrollable.

* added Magnifier for iOS and Android

Co-authored-by: Anthony Oleinik <oleina@google.com>

Co-authored-by: Renzo Olivares <roliv@google.com>

Dragging the base text selection handle on Apple makes it the extent.

This reverts commit 4ec4c249.

Bug fix for focusing a field with right click on existing selection (Mac and iOS)

* Use `curly_braces_in_flow_control_structures` for `widgets`

* fix comments

* fix comments

* Support global selection

* addressing comments

* add new test

* Addressing review comments

* update

* addressing comments

* addressing comments

* Addressing comments

* fix build

* Implement trackpad gestures in framework

* Touch and Pan/Zoom pointers have separate IDs now

* Handle trackpad pointer device type

* Respect supportedDevices for pan/zoom events

* Update after rebase

* Fix check failures

* Avoid error with very short drags

* Address feedback

* Refactor drag event handler

* Address more feedback

* Add some missing punctuation

* Add fadeDuration back to TextSelectionOverlay

* fix build and add dart fix

* format

* add test

This reverts commit c74a646b.

* Clean up ClipboardStatusNotifier

* fix

* fix test

* more refactaaaaagit add .

* Hide toolbar when selection is out of view

* properly dispose of toolbar visibility listener

* Add test

* rename toolbarvisibility

* Make visibility for toolbar nullable

* Properly dispose of toolbar visibility listener

* Merge visibility methods into one

* properly dispose of start selection view listener

* Add some docs

* remove unnecessary null check

* more docs

* Update dispose order
Co-authored-by: Renzo Olivares <roliv@google.com>

* Refactor TextSelectionOverlay

* fix test

* remove print

* fix more tests

* update

* added tests

* fix comments

* fmt

* fix test

* addressing comment

* remove dispose

* remove new line

* Unify Text selection API

* fix test

* further simplify

* fix more tests

* styling change