CMCL-0000: Group Framing works with Confiner 2D

[glabute]

Purpose of this PR

GroupFraming and Confiner2D did not play well together.
Slack thread: https://unity.slack.com/archives/C4P4KJR9A/p1713367131830879

This PR introduces a special compatibility mode to handle this common use-case. GroupFraming checks for the presence of Confiner2D and if it finds one, it runs in the Body stage (with an early execution order) so that it happens before Confiner2D. Also, in this mode it monitors the ortho size and invalidates the confiner lens cache when the ortho size changes.

Testing status

• Added an automated test
• Passed all automated tests
• Manually tested

Documentation status

• Updated CHANGELOG
• Updated README (if applicable)
• Commented all public classes, properties, and methods
• Updated user documentation

Technical risk

low

[AntoineCharton]

Nice change! Can you check why the isolation test aren't compiling?

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 0% with 25 lines in your changes are missing coverage. Please review.

Project coverage is 27.02%. Comparing base (2b73baa) to head (77d14c4).
Report is 2 commits behind head on main.

Files	Patch %	Lines
...hine/Runtime/Behaviours/CinemachineGroupFraming.cs	0.00%	25 Missing ⚠️

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Additional details and impacted files

@@            Coverage Diff             @@
##             main     #975      +/-   ##
==========================================
- Coverage   27.06%   27.02%   -0.04%     
==========================================
  Files         248      248              
  Lines       27856    27877      +21     
==========================================
- Hits         7540     7535       -5     
- Misses      20316    20342      +26     

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