Consider re-implementing local inspection on Dart files to run pub (FlutterDependencyInspection)

The `LocalInspectionTool`s in the Flutter and Dart IntelliJ plugins have been causing more headache and possible performance issues than they have been worth, see https://github.com/flutter/flutter-intellij/issues/7623 for some context.

This feature was the ability to see `pub get`, and other `pub` actions, at the top of your Dart file if `pub` needed to be run. The functionality was split across the two IntelliJ plugins. After the implementation of the Dart Workspaces feature, validation of a successful `pub get` is more complicated than it was when this original `LocalInspectionTool`s were implemented. In the IDEA framework `LocalInspectionTool`s are run frequently and precaution around not searching up directory structures (read: trying to avoid possible performance issues), easily leads to annoying false positives-- a notification at the top every dart file that can't be dismissed.

Note: the functionality for having the `pub` actions at the top of the pubspec.yaml is still preserved with `FlutterPubspecNotificationProvider` and `DartEditorNotificationsProvider` (`EditorNotificationProvider`s).

This issue is open as a place holder to incase the feature is missed. If we do re-implement it, consider:

- 1 implementation, not 2, both for debugging issues as well as not introducing lag in the plugin
- and, having the functionality be disabled by default.