A bunch of random cleanup things I found while doing MenuBar development.

Changes an if test to an assert in binding.dart, since the if should always be true.
Adds the default ShortcutRegistrar that should have been in the ShortcutRegistry PR.
Moves a debug message in the FocusManager to print the result after the focus change instead of before.
Reorders the test parameters in theme_data_test.dart to match the order of the theme data fields everywhere else.

* Use `curly_braces_in_flow_control_structures` for `material`

* include test/material

* add back removed comments

* `Switch`: Add an interactive examples

* Update docs

* Update doc

* Support global selection

* addressing comments

* add new test

* Addressing review comments

* update

* addressing comments

* addressing comments

* Addressing comments

* fix build

* Reland "Fix Backbutton is not displayed when there is a endDrawer (#102093)"

This reverts commit a4a8e73b.

* add todos

Flutter uses `vswhere.exe` to find Visual Studio installations and determine if they satisfy Flutter's requirements. However, `vswhere.exe`'s JSON output is known to contain bad UTF-8. This change ignores bad UTF-8 as long as they affect JSON properties that are either unused, or, used only for display purposes by Flutter.

Fixes: https://github.com/flutter/flutter/issues/102451

Revert "Add ability for `ModalRoutes` to ignore pointers during transitions and do so on `Cupertino` routes (#95757)" (#104520)

This reverts commit 4c0b0be2.

Adds a bit more clarifying documentation to the implementation of the
outputFollowsExit case, and adds tests that verify the behaviour of
stderr, stdout of processes launched via FakeProcessManager.

Specifically:
* Verifies that stderr, stdout are not emitted immediately after process
  exit if outputFollowsExit is true. They must be emitted at least one
  turn through the event loop later.
* Verifies that ProcessResult.stderr, stdout have the type documented
  according to the encoding passted to Process.run/runSync:
  * List<int> if null is passed as the encoding.
  * String (in the default system encoding) if no encoding is specified.
  * String (in the specified encoding) if an encoding is specified.

This is additional testing relating to refactoring landed in:
https://github.com/flutter/flutter/pull/103947

Issue: https://github.com/flutter/flutter/issues/102451