Report ABI version errors before diagnostics and other errors

Otherwise they're difficult to find in the end of the compiler messages
Fix JVM type mapping of arrays of type variables

 #KT-4262 Fixed
 #KT-5056 Fixed
Fix stdlib tests on JVM

 #KT-5064 Open
Move JvmMethodSignature to frontend.java
Signature comparison used to find super functions in SignaturesPropagationData

 #KT-4509 Fixed
Minor. More specific return type