ComponentSource robustness: add `ComponentSourceTestBase::testSettings()`

I'd like to see JsComponentTest to look more like BlockComponentTest and SingleDirectoryComponentTest. Not having a setup() will make easier to test the discovery too, aside of providing consistency in the 3 tests.

We could use some dataProviders here and there and avoid some helper methods in JsComponentTest

@isholgueras expanded the scope to also cover 📌 [PP-1] Add `JsComponent` unit test Active .

Automatically closed - issue fixed for 2 weeks with no activity.