[tests] Add a test to verify that AppDomain.CurrentDomain.BaseDirectory is always something. Fixes #12687.

[rolfbjarne]

Fixes #12687.

[vs-mobiletools-engineering-service2]

❌ [PR Build] Tests failed on Build ❌

Tests failed on Build.

• Azure DevOps
• Html Report (VSDrops)

API diff

✅ API Diff from stable

View API diff

• iOS vsdrops gist
• macOS vsdrops gist
• macCat vsdrops gist
• macCatiOS gist
• tvOS vsdrops gist
• watchOS vsdrops gist

API & Generator diff

✅ API Diff (from PR only) (no change)
✅ Generator Diff (only version changes)

GitHub pages

Results can be found in the following github pages (it might take some time to publish):

• Test results
• API diff
• API & Generator diff

Test results

2 tests failed, 132 tests passed.

Failed tests

• dont link/Mac Catalyst [dotnet]/Release [dotnet]: TimedOut (Execution timed out after 1200 seconds.
  No test log file was produced)
• interdependent-binding-projects/Mac Catalyst [dotnet]/Debug [dotnet]: TimedOut (Execution timed out after 1200 seconds.
  No test log file was produced)

Pipeline on Agent XAMBOT-1100.BigSur
Merge 291db0e into 3ffabb1

[rolfbjarne]

Test failure is unrelated (https://github.com/xamarin/maccore/issues/2414).