[AA] Add symbol tests for symbols from JS klibs

Use test compiler runner to compile JS libraries. Determine compiler
by the specified TARGET_PLATFORM. Add tests for dynamic type and
JS-specific .proto extensions.

Refactor the code for mock library compilation to make the switch
between platforms more straightforward.

KTIJ-27566
KT-63217

analysis/low-level-api-fir/testData/getOrBuildFirBinary/js/fileJsModule.txt

@@ -0,0 +1,8 @@
+KT element: KtNamedFunction
+KT element text:
+public external fun foo(): kotlin.Unit { /* compiled code */ }
+FIR element: FirSimpleFunctionImpl
+FIR source kind: KtRealSourceElementKind
+
+FIR element rendered:
+public final external [ResolvedTo(BODY_RESOLVE)] fun foo(): R|kotlin/Unit|