playwright: Update to latest versions and add new page objects

[ndoschek]

What it does

• Update playwright to the latest version
  • Update test configuration to adapt to latest version
  • Remove obsolete multiple config files and scripts
• Add page objects for OutputView, OutputChannel, Toolbar, MonacoEditor
• Extend tests by testing the new page objects
• Extend ExplorerView tests with compact folders
• Extend QuickCommand tests
• Update GETTING_STARTED.md and DEVELOPING.md
• Update build script to use ensure clean and lint are called
  • Ensure all necessary playwright dependencies are installed on initial build

Signed-off-by: Nina Doschek [email protected]

How to test

• Run playwright tests via yarn test:playwright from root directory

Review checklist

• As an author, I have thoroughly tested my changes and carefully followed the review guidelines

Reminder for reviewers

• As a reviewer, I agree to behave in accordance with the review guidelines

[ndoschek]

Hi @planger, as you already had an initial look on my changes, could you perhaps suggest additional reviewers for this PR? Thank you!

[planger]

@vince-fugnitto Would you maybe have time to look into this change? I've already reviewed it internally.
Marc has done some work on Playwright recently as well, but I've already asked him to review #12381, so I don't want to overload him :-)

[vince-fugnitto]

The changes look good to me, I confirmed they pass locally and during CI 👍
I'm not sure if @marcdumais-work would like to take a look as well but given it works it is likely not necessary. We can keep an eye out if things get flaky.

[planger]

@vince-fugnitto Thanks for the review! Let's merge this PR then and observe the stability. I'll rebase #12381 where Marc is added as a reviewer on top to make sure both changes work in combination.

[vince-fugnitto]

I was hoping to get #12320 in first due to issues with the "out-of-date" CI check but it's fine.

[planger]

Oh I see... sorry about that! I saw that Nina rebased and all checks passed. So I thought I'd save the build cycle and rebase mine (as it is the smaller change anyway) :-)