Fixes #111325

Adds the ability to specify Flutter framework tests as flaky, allowing them to be uploaded to Skia Gold for visual confirmation that a flake has been fixed. Prior to this change, there was no way to see if a flake had been fixed, the test would be re-enabled and then the tree would break, letting us know it was still flaky.
This will prevent a test from breaking the tree while it is in flaky mode.

Also added tech debt tracking and analyzer enforcement.

• will need to update wiki https://github.com/flutter/flutter/wiki/Writing-a-golden-file-test-for-package:flutter

Pre-launch Checklist

• I read the Contributor Guide and followed the process outlined there for submitting PRs.
• I read the Tree Hygiene wiki page, which explains my responsibilities.
• I read and followed the Flutter Style Guide, including Features we expect every widget to implement.
• I signed the CLA.
• I listed at least one issue that this PR fixes in the description above.
• I updated/added relevant documentation (doc comments with ///).
• I added new tests to check the change I am making, or this PR is test-exempt.
• All existing and new tests are passing.

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