TODO AND COMMENT: Refine JetSourceFilterScope (classes in library classes can be ignored, but we also add hack)
++ refine JetSourceFilterScope
++ JetSourceFilterScope
Drop IDEAConfig
++ drop idea config
Insert type arguments after replacing expression
ProjectStructureUtil
TO SPLIT: Implement IDE modules
Introduce MultiModuleAnalysisTest

Checks that analysis produces expected diagnostics when configured by real IDEA Module
Remove additional logic for comparing files in JavaClassFinderImpl
ResolveSessionForBodies is not ModificationTracker
TEMP: some scope magic for profiling
Introduce packageExists utility in PackageIndexUtil
Use PackageIndexUtil#packageExists in IDELightClassGenerationSupport
Use PackageIndexUtil#packageExists utility in PluginDeclarationProviderFactory
FIXUP: remove unoptimal code in JetSourceFilterScope
Improve SyntheticFilesFilteringScope performance
COMMENT: JetSourceFilterScope performance
DRAFT: ATTEMPT at packages indices
DRAFT SubpackagesIndexService.kt