Add debug strings to frontend scopes-related structures

Such as:
- PackageFragmentProviders, and, in particular,
CompositePackageFragmentProviders
- JavaPackageFragments
- Scopes produced by those providers

The rationale is that a lot of frontend-facing bugs (like red code) are
easily recognizeable in resolution. But at that point you just see a
bunch of scopes, without meaningful toStrings, you don't know who has
produced them, and what's exactly wrong.

With this commit it should make debugging slightly easier: now at least
you'll be able to see that "this scope is a scope of package fragment
for foo.bar of module baz" and decide whether the declaration should or
should not have been resolved from such scope.

js/js.frontend/src/org/jetbrains/kotlin/frontend/js/di/injection.kt

@@ -66,7 +66,9 @@ fun createContainerForJS(
         val packagePartProviders = mutableListOf(get<KotlinCodeAnalyzer>().packageFragmentProvider)
         val moduleDescriptor = get<ModuleDescriptorImpl>()
         packagePartProviders += additionalPackages
-        moduleDescriptor.initialize(CompositePackageFragmentProvider(packagePartProviders))
+        moduleDescriptor.initialize(
+            CompositePackageFragmentProvider(packagePartProviders, "CompositeProvider@createContainerForJS for $moduleDescriptor")
+        )
     }
     return storageComponentContainer
 }