[Wasm] Move external RTT checkers to web.common and reuse in Wasm

#KT-56849

compiler/testData/diagnostics/wasmTests/jsInterop/rtti/nativeInterfaceClassLiteral.kt

@@ -0,0 +1,8 @@
+// FIR_IDENTICAL
+external interface I
+
+typealias TA = I
+fun box() {
+    println(<!EXTERNAL_INTERFACE_AS_CLASS_LITERAL!>I::class<!>)
+    println(<!EXTERNAL_INTERFACE_AS_CLASS_LITERAL!>TA::class<!>)
+}