[FIR] Consider fullyExpandedType instead of original type in isSubtypeForTypeMismatch, consider lookupTag in isError method

compiler/testData/diagnostics/tests/generics/projectionsScope/unsafeVarianceInAliasedFunctionalType.fir.kt

@@ -1,11 +0,0 @@
-class Foo<out T>(val baz: Baz<T>)
-
-class Bar {
-    val foo: Foo<*> = TODO()
-
-    fun <T> bar(): Baz<T> {
-        return <!RETURN_TYPE_MISMATCH!>foo.baz<!>
-    }
-}
-
-typealias Baz<T> = (@UnsafeVariance T) -> Unit

compiler/testData/diagnostics/tests/generics/projectionsScope/unsafeVarianceInAliasedFunctionalType.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 class Foo<out T>(val baz: Baz<T>)
 
 class Bar {