GetTotalPauseDuration implementation

[cshung]

Fixes #66036

• Mono implementation - we will probably merge before that is done.
• Organize the EE -> GC interfaces such that it is version resilience.
• Testing
• API Documentation

[ghost]

Note regarding the new-api-needs-documentation label:

This serves as a reminder for when your PR is modifying a ref *.cs file and adding/modifying public APIs, to please make sure the API implementation in the src *.cs file is documented with triple slash comments, so the PR reviewers can sign off that change.

[ghost]

I couldn't figure out the best area label to add to this PR. If you have write-permissions please help me learn by adding exactly one area label.

[ghost]

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Issue Details

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Fixes #66036

• Mono implementation - we will probably merge before that is done.
• Organize the EE -> GC interfaces such that it is version resilience.
• Testing
• API Documentation

Author:	cshung
Assignees:	cshung
Labels:	area-GC-coreclr, new-api-needs-documentation
Milestone:	-