## Description
Adds defaults that use tokens to define default `iconSize` and `iconColor` values. Previously, the Material 3 token values for button icon sizes and colors were not being used as defaults when the `ButtonStyleButton.defaultStyleOf` function returned the default values.
Adds tests to make sure appropriate `ButtonStyle` fields are populated when defaultStyle is called on buttons.
Updated documentation for `defaultStyleOf` to indicated that not _all_ fields need to be non-null, since some fields make sense to be null (e.g. `fixedSize`) because they would otherwise override the behavior of other fields in the same `ButtonStyle`.
## Tests
- Added tests to make sure that the appropriate fields are non-null in the default button styles for each type of button.
## Description
This improves defaults generation with logging, stats, and token validation.
This PR includes these changes:
* introduce `TokenLogger`, with a verbose mode
* prints versions and tokens usage to the console
* outputs `generated/used_tokens.csv`, a list of all used tokens, for use by Google
* find token files in `data` automatically
* hide tokens `Map`
* tokens can be obtained using existing resolvers (e.g. `color`, `shape`), or directly through `getToken`.
* tokens can be checked for existence with `tokenAvailable`
* remove version from template, since the tokens are aggregated and multiple versions are possible (as is the case currently), it does not make sense to attribute a single version
* improve documentation
## Related Issues
- Fixes https://github.com/flutter/flutter/issues/122602
## Tests
- Added tests for `TokenLogger`
- Regenerated tokens, no-op except version removal
## Future work
A future PR should replace or remove the following invalid tokens usages
<img width="578" alt="image" src="https://github.com/flutter/flutter/assets/6655696/b6f9e5a7-523f-4f72-94f9-1b0bf4cc9f00">
Fixes#122250. This PR is to make sure all the MaterialStateProperty defaults are able to correctly resolve different states.
* When a widget is pressed, it is also hovered, so we need to put the `MaterialState.pressed` check before `MaterialState.hovered`.
* When a widget is focused, the widget should still be able to be hovered, so we should check `MaterialState.hovered` before `MaterialState.focused`.
* There are also cases like in _InputDecoratorDefaultsM3, the `MaterialState.disabled` should be checked before `MaterialState.error`.
the order should be disabled, (error), pressed, hovered, focused.
* Added support for surfaceTintColor and shadowColor to the Dialog widgets.
* Updated the defaults for Material.shadowColor and Material.surfaceTint to allow turning off the features with a transparent color.
* Added support for shadowColor and surfaceTintColor for Drawer widget.
