Local and GitHub playwright testing improvements

[myieye]

Description

Various minor playwright improvements:

• Cache playwright browsers in GHA (per playwright version as documented). Not a huge performance boost, but not a huge change either
• Upload the playwright results as a GitHub artifact, which is then available for download (see screenshot)
• Allow passing playwright params to make file. E.g. make playwright-tests params="--headed"
• Allow running make files with npm (I find it very handy for the commands to be directory independent) E.g. npm run make playwright-tests params="--headed"
• Wait for forgotten promise in globalSetup.ts and add ts-lint rule to watch for cases like this
• Close browserContexts in globalSetup.ts, because: (1) it's documented as best practice, (2) it doesn't break anything and (3) it eliminates a potential culprit of "socket hang up" mentioned in bug: Race condition in Playwright webServer config #1402

Type of Change

• New feature

Screenshots

Checklist

• I have performed a self-review of my own code
• I have reviewed the title/description of this PR which will be used as the squashed PR commit message
• I have commented my code, particularly in hard-to-understand areas

[github-actions]

Unit Test Results

368 tests   368 ✔️  9s ⏱️
    1 suites      0 💤
    1 files        0 ❌

Results for commit ee6687a.

♻️ This comment has been updated with latest results.

[megahirt]

These are great additions, thanks @myieye !