[LL FIR] KT-57207 Combine Java symbol providers

- `LLFirCombinedJavaSymbolProvider` combines multiple
  `JavaSymbolProvider`s. Its advantages are: combined index access,
  caching, classpath order disambiguation.
- Scopes can still be optimized with a combined scope instead of a naive
  union scope.

^KT-57207 fixed

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/JavaUtils.kt

@@ -52,7 +52,7 @@ val JavaClass.classKind: ClassKind
         else -> ClassKind.CLASS
     }
 
-internal fun JavaClass.hasMetadataAnnotation(): Boolean =
+fun JavaClass.hasMetadataAnnotation(): Boolean =
     annotations.any { it.classId?.asSingleFqName() == JvmAnnotationNames.METADATA_FQ_NAME }
 
 internal fun Any?.createConstantOrError(session: FirSession): FirExpression {