Real-time Collaboration: Fix error when collaboratorInfo is null

[maxschmeling]

What?

When retrieving collaborator info takes too long, the collaboratorInfo property can be null and cause exceptions. This change fixes that issue.

Why?

User reported errors in real-world environments.

Testing Instructions

1. Add a delay in setCurrentCollaboratorInfo (in packages/core-data/src/awareness/base-awareness.ts) with await new Promise( ( resolve ) => setTimeout( resolve, 5000 ) );
2. Open a post in two windows
3. Put your cursor in a paragraph
4. Prior to this fix, you'll see an error and content disappear

[ingeniumed]

The static analysis failure is due to a change in trunk not being used, while the other two test failures are due to a change in recordHandlers that's not in trunk. It's unrelated to this PR

[github-actions]

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Co-authored-by: maxschmeling <maxschmeling@git.wordpress.org>
Co-authored-by: ingeniumed <ingeniumed@git.wordpress.org>

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