This reverts commit c26ed03c.

* Migrate to ChannelBuffers.push

* Move TestDefaultBinaryMessenger to its own file

* Apply deprecations and fix usages

This reverts commit 67d8556b.

* Fix rendereditable to check the latest text before setting the selection

* add regression comment

* addressing comments and fix tests

Text editing shortcuts involving the arrow keys are no longer handled by RenderEditable's RawKeyboardListener, they use the new Shortcuts setup.  First PR in a plan to port all text editing keyboard handling to shortcuts.

* Adds set text semantics action to render editable

* addressing comments

* re-enable test

* fix test

* fix more test

* fix bad merge

* addressing comment

* update dynamic to Object?

* Hide selection handles from semantics

* update comment

This reverts commit a46139a2.

Revert "TextField and last input character should visible on the screen when the cursor is not shown (#74722)" (#75532)

This reverts commit cd771404.

TextField and last input character should visible on the screen when the cursor is not shown (#74722)

Very simple right-click context menu for Windows and Linux in a Material-esque style.

A very minimal right-click menu for Mac desktop.

  * Making a custom iOS-style text selection menu is now much easier.
  * Exposes a new widget for the toolbar, a new widget for the buttons, and a new widget for the layout.