Checked that KT-4453 has been fixed recently by change in TipsManager
Completion: do not bold top-level functions
Completion: corrected presentation for extension properties
Completion: bold immediate members for extensions too
Removed code which does not seem to be needed at all
Added tests
Moved method checkIsExtensionCallable from ExpressionTypingUtils to TipsManager (converting it to Kottlin)
Moved methods for checking extensions applicability from TipsManager to extensionUtils.kt (and made them all extension methods)
Renamed TipsManager
Made ReferenceVariantsHelper class instead of object making method signatures shorter
Minor code refactorings
Convert AnalyzeExhaust to Kotlin and make it a data class
Use KotlinCacheService directly in IDELightClassGenerationSupport
Converter: use ide resolve through a dedicated interface

Eliminate direct usages of ResolveSession
Fix getModuleInfo for elements in code fragments
~ for rr