Migrate everything from Shouldly to FluentAssertions

[myieye]

Migrates all our assertion from Shouldy to FluentAssertions as decided at our team meeting.

This should get User typeahead enabled for non-admin project managers unstuck.

Questionable:
- I created created custom assertions (e.g. ShouldNotBeNull()) as we discussed, but I put the class right in the Testing namespace
- I added a project reference from MiniLcm.Tests to Testing so it gets the custom assertions
- Adding that reference resulted in some package version differences that I resolved by updating them

EDIT: I just updated to a FluentAssertions 7 prerelease and they solved the problem for us.

[github-actions]

C# Unit Tests

90 tests   90 ✅  5s ⏱️
14 suites   0 💤
 1 files     0 ❌

Results for commit c5089dd.

♻️ This comment has been updated with latest results.

[hahn-kev]

looks good, though I don't like miniLcm tests referencing our lexbox tests

[myieye]

6 dotnet failures. I'm going to try again.

And, it looks like my back-button fix doesn't work in Firefox 😢

[rmunn]

@myieye - The 6 dotnet failures are all caused by the same one test:

languageforge-lexbox/backend/Testing/Services/SendReceiveService.cs

Line 98 in 3a69401

srResult.ShouldContain("no changes from others");

The actual output is "No changes from others", with an uppercase N. ShouldContain in Shouldly was case-insensitive, but Should().Contain() is case-sensitive. We can either change that one to Should().ContainEquivalentOf() which is case-insensitive, or we can change the expected text to include a capital N. Given the large amount of text in the Send/Receive output (hundreds of lines), I'd suggest changing the expected text to be "No changes" with the capital N, because the case-sensitive comparison is likely to be faster to run.

[myieye]

@rmunn Thanks very much for fixing the .NET tests! There was just an unrelated Playwright failure, so this was good to merge 👍