[LL FIR] KT-57220 Optimize & combine synthetic function symbol providers

- Dependency symbol providers contained a lot of useless
  `FirExtensionSyntheticFunctionInterfaceProvider`s, because such a
  provider only generates function classes from compiler plugins. If
  there aren't any such `FunctionTypeKind`s in the session, there is no
  need to even add the provider.
- `FirExtensionSyntheticFunctionInterfaceProvider`s that are added to
  the list of dependency providers despite this optimization will now be
  combined in `LLFirCombinedSyntheticFunctionSymbolProvider`. It checks
  `ClassId` heuristics once, which is more efficient than checking them
  in every provider separately.

compiler/fir/tree/src/org/jetbrains/kotlin/fir/types/FirFunctionTypeKindService.kt

@@ -23,6 +23,16 @@ abstract class FirFunctionTypeKindService : FirSessionComponent {
         return extractor.hasKindWithSpecificPackage(packageFqName)
     }
 
+    /**
+     * Returns all package names for which [getKindByClassNamePrefix] may return a [FunctionTypeKind].
+     */
+    fun getFunctionKindPackageNames(): Set<FqName> = extractor.getFunctionKindPackageNames()
+
+    /**
+     * Whether [getKindByClassNamePrefix] may return a [FunctionTypeKind] added by a compiler plugin.
+     */
+    fun hasExtensionKinds(): Boolean = extractor.hasExtensionKinds()
+
     abstract fun extractSingleSpecialKindForFunction(functionSymbol: FirFunctionSymbol<*>): FunctionTypeKind?
     abstract fun extractAllSpecialKindsForFunction(functionSymbol: FirFunctionSymbol<*>): List<FunctionTypeKind>
     abstract fun extractAllSpecialKindsForFunctionTypeRef(typeRef: FirFunctionTypeRef): List<FunctionTypeKind>