Basic version of CONFLICTING_PLATFORM_DECLARATIONS diagnostic

 #KT-1 In Progress
Repoting platform declarations clashes in CLI compiler for JVM

 #KT-1 In Progress
Compilation fixed
Cache KotlinLightClassForPackage instances per project
Report clashing signatures in the IDE

Expose extra diagnostics about platform signature clashes from light class data

 #KT-1 In Progress
Diagnostic tests for duplicate JVM signatures
JvmDeclarationOrigin used in newField()
JvmDeclarationOrigin used in newMethod()
JvmDeclarationOrigin used in newVisitor()
JvmDeclarationOrigin used in newClassBuilder()
Package part and facade origins supported
TraitImpl origin supported
JvmDeclarationOrigin used in FunctionCodegen.generateMethod()
DelegationToTraitImpl origin kind supported
Highlight only declarations, without body, on platform signature clashes
CONFLICTING_PLATFORM_DECLARATIONS moved to a JVM-specific class
Test data fixed
JvmDeclarationOrigin moved to frontend.java
Filtering duplicate diagnostics for package facades and package parts
Highlight property accessor headers only, without body