Chore/improve e2e tests in gha

[myieye]

As discussed in our team meeting:

• We want Playwright tests to run on frontend changes. This is the easiest way to do that. I could have gotten smart and filtered out viewer changes. But, I wasn't convinced that it was worth it.
• Also as discussed, we'll just disable the test (in Firefox) that uses a header not supported in Firefox. A client-side only fix might be worthwhile in the future.

[github-actions]

UI unit Tests

12 tests   12 ✅  0s ⏱️
 4 suites   0 💤
 1 files     0 ❌

Results for commit e963418.

[github-actions]

C# Unit Tests

90 tests  ±0   90 ✅ ±0   4s ⏱️ -1s
14 suites ±0    0 💤 ±0 
 1 files   ±0    0 ❌ ±0 

Results for commit e963418. ± Comparison against base commit a525563.