[camera_avfoundation] Wrappers swift migration - part 3

[RobertOdrowaz]

Migrates camera wrappers as part of flutter/flutter#119109

This PR migrates wrappers to Swift:

• FLTCaptureDevice
• FLTCaptureSession
• FLTFormatUtils

In line with Swift conventions, the FLT prefixes are removed. The Default class implementations are replaced with protocol conformance on base AV classes.

Pre-Review Checklist

• I read the Contributor Guide and followed the process outlined there for submitting PRs.
• I read the Tree Hygiene page, which explains my responsibilities.
• I read and followed the relevant style guides and ran the auto-formatter.
• I signed the CLA.
• The title of the PR starts with the name of the package surrounded by square brackets, e.g. [shared_preferences]
• I linked to at least one issue that this PR fixes in the description above.
• I updated pubspec.yaml with an appropriate new version according to the pub versioning philosophy, or I have commented below to indicate which version change exemption this PR falls under¹.
• I updated CHANGELOG.md to add a description of the change, following repository CHANGELOG style, or I have commented below to indicate which CHANGELOG exemption this PR falls under¹.
• I updated/added any relevant documentation (doc comments with ///).
• I added new tests to check the change I am making, or I have commented below to indicate which test exemption this PR falls under¹.
• All existing and new tests are passing.

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Note: The Flutter team is currently trialing the use of Gemini Code Assist for GitHub. Comments from the gemini-code-assist bot should not be taken as authoritative feedback from the Flutter team. If you find its comments useful you can update your code accordingly, but if you are unsure or disagree with the feedback, please feel free to wait for a Flutter team member's review for guidance on which automated comments should be addressed.

Footnotes

1. Regular contributors who have demonstrated familiarity with the repository guidelines only need to comment if the PR is not auto-exempted by repo tooling. ↩ ↩² ↩³

[gemini-code-assist]

Code Review

This pull request migrates FLTCaptureDevice, FLTCaptureSession, and FLTFormatUtils classes to Swift, removing the FLT prefixes and replacing Default class implementations with protocol conformance on base AV classes. The changes include modifications to the example project and the core implementation, updating tests and adapting to the new Swift conventions. The review focuses on ensuring correctness, maintainability, and adherence to the project's coding standards.

[hellohuanlin]

Hi, could you sweep through gemini's comment first?

[RobertOdrowaz]

@hellohuanlin done, there was nothing meaningful there, a bunch of comments regarding argument names in mocks and some streight up invalid suggestions