Simplify usages of IncrementalPackageFragment and related code

Since its scope is now empty, no descriptor now has a container that is an
instance of IncrementalPackageFragment -> a lot of code is not needed anymore

compiler/daemon/daemon-common/src/org/jetbrains/kotlin/daemon/common/CompilerCallbackServicesFacade.kt

@@ -48,9 +48,6 @@ interface CompilerCallbackServicesFacade : Remote {
     @Throws(RemoteException::class)
     fun incrementalCache_getObsoleteMultifileClassFacades(target: TargetId): Collection<String>
 
-    @Throws(RemoteException::class)
-    fun incrementalCache_getMultifileFacade(target: TargetId, partInternalName: String): String?
-
     @Throws(RemoteException::class)
     fun incrementalCache_getPackagePartData(target: TargetId, partInternalName: String): JvmPackagePartProto?
 
@@ -91,4 +88,4 @@ class RmiFriendlyCompilationCanceledException : Exception(), Serializable {
     companion object {
         private val serialVersionUID: Long = 8228357578L // just a random number, but should never be changed to avoid deserialization problems
     }
-}
+}