[FIR] Introduce utility searching for classifier symbol by ClassId

There were places which created lookupTag from classId just to call
  `lookupTag.toSymbol(session)`

compiler/fir/providers/src/org/jetbrains/kotlin/fir/resolve/providers/FirSymbolProvider.kt

@@ -116,6 +116,10 @@ fun FirSymbolProvider.getRegularClassSymbolByClassId(classId: ClassId): FirRegul
     return getClassLikeSymbolByClassId(classId) as? FirRegularClassSymbol
 }
 
+fun ClassId.toSymbol(session: FirSession): FirClassifierSymbol<*>? {
+    return session.symbolProvider.getClassLikeSymbolByClassId(this)
+}
+
 val FirSession.symbolProvider: FirSymbolProvider by FirSession.sessionComponentAccessor()
 
 const val DEPENDENCIES_SYMBOL_PROVIDER_QUALIFIED_KEY: String = "org.jetbrains.kotlin.fir.resolve.providers.FirDependenciesSymbolProvider"