Fix #3726, #3727 - Playlist not showing in Toast or Share Menu for some sites

[Brandon-T]

Summary of Changes

• Some sites are using setAttribute and others are setting the src property directly.
• This code hooks both so that playlist works properly on all sites.
• This was a regression due to the performance fix that removed mutation observers.
• We will have no performance impact with this code, but we'll have support for more sites :)

This pull request fixes #3726, #3727

Submitter Checklist:

• Unit Tests are updated to cover new or changed functionality
• User-facing strings use NSLocalizableString()

Test Plan:

Screenshots:

Reviewer Checklist:

• Issues include necessary QA labels:
  • QA/(Yes|No)
  • release-notes/(include|exclude)
  • bug / enhancement
• Necessary security reviews have taken place.
• Adequate unit test coverage exists to prevent regressions.
• Adequate test plan exists for QA to validate (if applicable).
• Issue is assigned to a milestone (should happen at merge time).