rewriting fix: twitter video in embedded tweets

[ikreymer]

Description

Improve twitter rewrite to also use mp4 for videos in twitter embed

Motivation and Context

Partial fix to embedded tweets, as described in webrecorder/browsertrix-crawler#160

Types of changes

• Replay fix (fixes a replay specific issue)
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added or updated tests to cover my changes.
• All new and existing tests passed.