[FIR] Use isSubtypeOfClass with platform types mapping instead of isSubtypeOf during checking CAST_NEVER_SUCCEEDS

Refactor and generalize code

^KT-62783 Fixed

compiler/fir/analysis-tests/testData/resolve/checkers/unsuccessfullCastToStartProjectedType.kt

@@ -5,5 +5,5 @@ class Foo1<A> : Foo<Int>()
 class Foo2 : Foo<Int>()
 
 fun process(foo: Foo<Long>) {
-    foo <!CAST_NEVER_SUCCEEDS!>as<!> Foo1<*>
+    foo as Foo1<*>
 }