RUM-6223 Implement Hidden Override logic

[mariedm]

What and why?

This PR implements the logic for the hidden property in Session Replay, as a continuation of #2058, which introduces Fine-Grained Masking (FGM) overrides.

How?

• Added a new SessionReplayOverrideExtension property to ViewAttributes.
• In the view recorder, it now checks for the hiddenPrivacy property.
• When this property is set, it returns a placeholder frame for the hidden view and ignores its child views.
• Renamed hiddenPrivacy to hide, as it is now a Bool, making the name more intuitive after converting from an enum.
• Addressed this comment from the previous PR to clean up the SessionReplayOverrideExtension implementation.

Review checklist

• [x] Feature or bugfix MUST have appropriate tests (unit, integration)
• [x] Make sure each commit and the PR mention the Issue number or JIRA reference
• [ ] Add CHANGELOG entry for user facing changes

[datadog-datadog-prod-us1[bot]]

Datadog Report

Branch report: RUM-6223-implement-hidden-override-logic Commit report: f3b7c1a Test service: dd-sdk-ios

:white_check_mark: 0 Failed, 3485 Passed, 0 Skipped, 2m 21.24s Total Time :small_red_triangle_down: Test Sessions change in coverage: 3 decreased, 5 increased, 6 no change

:small_red_triangle_down: Code Coverage Decreases vs Default Branch (3)

• test DatadogCoreTests tvOS 78.44% (-0.25%) - Details
• test DatadogTraceTests iOS 54.24% (-0.02%) - Details
• test DatadogInternalTests tvOS 79.53% (-0.02%) - Details