Stardew Vallet Tests - Restructure the tests that validate Mods + ER together, improved performance

[agilbert1412]

What is this fixing or adding?

Discord Convo between Black Sliver and myself starts here: https://discord.com/channels/731205301247803413/1214608557077700720/1333158359632969810

Short version is:

• Reduce the scope of the test (Don't test mods that don't interact with ER, don't test ER settings that are subsets of Buildings)
• Reduce the amount of things tested (No need to care about stray items, the other tests check that already)
• Unroll the subtests into individual tests to play better with multithreading environments, leading to increased global performance for them.

Final improvement is about 65% on that one specific test, that took about 15 seconds out of the 90s test run. So globally, for stardew tests on my machine, it's nearly 10% improvement, probably better when multithreaded

How was this tested?

How do you think lmao

If this makes graphical changes, please attach screenshots.

Before:

After:

[Jouramie]

Nitpicking on typing, the rest LGTM.

[agilbert1412]

A fix to the "less maintainability" issue discussed in Discord will be available in #4560 once this is merged