[K2] Forbid to use "get class" in the context of string concat and equality

#KT-63941 Fixed

compiler/testData/diagnostics/tests/modifiers/const/kClassInStringConcatenation.kt

@@ -0,0 +1,11 @@
+// FIR_IDENTICAL
+annotation class Anno(val str: String)
+
+@Anno(<!ANNOTATION_ARGUMENT_MUST_BE_CONST!>"${A::class}"<!>)
+class A
+
+@Anno(<!ANNOTATION_ARGUMENT_MUST_BE_CONST!>B::class.toString()<!>)
+class B
+
+const val a = <!CONST_VAL_WITH_NON_CONST_INITIALIZER!>"${A::class}"<!>
+const val b = <!CONST_VAL_WITH_NON_CONST_INITIALIZER!>B::class.toString()<!>