Inject Parser.Clock for testing

[karlkfi]

• Update TestRun & TestRoot_Parse to validate the RootSync status
• Change SourceStatus, RenderingStatus, and SyncStatus to pointers and add DeepCopy methods, for easier generation of test permutations.
• Remove cacheForCommit.errs, which was only being used for testing errors in TestRun. Errors are now tested from the RSync status.

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