[tool] Migrate CleanCommand to modular dependency injection (#190742)

## Summary

Part 3 of the modular dependency injection migration.

Migrates `CleanCommand` to explicit constructor dependency injection via
`ToolContext` and `XcodeProjectInterpreter`, removing ambient access
from `FlutterCommand` and adding hermetic unit tests.

Part of https://github.com/flutter/flutter/issues/47161