Move some declarations between 'descriptors' and 'deserialization'

- Move the following from 'deserialization' to 'descriptors':
  NotFoundClasses.kt
  AdditionalClassPartsProvider.kt
  ClassDescriptorFactory.kt
  PlatformDependentDeclarationFilter.kt
  findClassInModule.kt
- Move the following form 'descriptors' to 'deserialization':
  BuiltInSerializerProtocol.kt
  builtInsPackageFragmentProvider.kt
- Extract a marker interface from BuiltInsPackageFragment and move its
  implementation to 'deserialization'
- Change the type of parameters in PlatformDependentDeclarationFilter
  and AdditionalClassPartsProvider to ClassDescriptor

This will help in getting rid of the circular dependency of
'descriptors' <-> 'deserialization'

js/js.serializer/src/org/jetbrains/kotlin/serialization/js/kotlinJavascriptPackageFragmentProvider.kt

@@ -17,6 +17,7 @@
 package org.jetbrains.kotlin.serialization.js
 
 import org.jetbrains.kotlin.descriptors.ModuleDescriptor
+import org.jetbrains.kotlin.descriptors.NotFoundClasses
 import org.jetbrains.kotlin.descriptors.PackageFragmentProvider
 import org.jetbrains.kotlin.descriptors.PackageFragmentProviderImpl
 import org.jetbrains.kotlin.incremental.components.LookupTracker