Refactors colorization to a centralized utility file, and makes it all conditional on `stdout` having ANSI escape support. This makes the output more readable on LUCI, which unlike the Cirrus log display doesn't handle ANSI.
Fixes https://github.com/flutter/flutter/issues/89392
Since the tool only needs to support back to Flutter 3.3 (the oldest version we still run CI with), this updates the tool to the corresponding minimum Dart version.
This allows the use of `super` parameters, so `dart fix --apply` was run to convert them all (and remove all the includes that were only needed for setting default values).
Also opportunistically cleans up a bunch of unnecessary, very old `dart:async` includes. (Other than those removals, the changes here are all `dart fix`-generated.)
Adds aliases for all commands that put the verb first, since currently they are inconsistent which can make it hard to remember (in particular, I often write `check-foo` instead of `foo-check` when running locally, and it fails).
Also does the long-overdue renaming of `test` to `dart-test`, since we now have `native-test`, `custom-test`, etc. `test` continues to work as an alias for individual muscle memory.
Packages are the primary conceptual object in the tool, but currently they are represented simply as Directory (or occasionally a path string). This introduces an object for packages and:
- moves a number of existing utility methods into it
- sweeps the code for the obvious cases of using `Directory` to represent a package, especially in method signatures and migrates them
- notes a few places where we should migrate later, to avoid ballooning the size of the PR
There are no doubt other cases not caught in the sweep, but this gives us a foundation both for new code, and to migrate incrementally toward as we find existing code that was missed.
To prep for making a combined command to run native tests across different platforms, rework `xctest`:
- Split analyze out into a new `xcode-analyze` command:
- Since the analyze step runs a new build over everything with different flags, this is only a small amount slower than the combined version
- This makes the logic easier to follow
- This allows us to meaningfully report skips, to better notice missing tests.
- Add the ability to target specific test bundles (RunnerTests or RunnerUITests)
To share code between the commands, this extracts a new `Xcode` helper class.
Part of https://github.com/flutter/flutter/issues/84392 and https://github.com/flutter/flutter/issues/86489
