Fix Playwright CI errors & update local instructions

[viniciusdc]

Reference Issues or PRs

close #2933

What does this implement/fix?

• Update readme notes for running the playwright tests locally;
• Fix issue with pytest x playwright async/sync conflicts by using pytest-xdist
• Include Makefile for easier setup
• Fix conda-store issues with extension after recent upgrade
• Add debug instructions

Put a x in the boxes that apply

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds a feature)
• Breaking change (fix or feature that would cause existing features not to work as expected)
• Documentation Update
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no API changes)
• Build related changes
• Other (please describe):

Testing

• Did you test the pull request locally?
• Did you add new tests?

How to test this PR?

Any other comments?

[marcelovilla]

LGTM! Thanks @viniciusdc !