FIR checker: report SUPERTYPE_NOT_INITIALIZED

Combined this and the checker of
SUPERTYPE_INITIALIZED_WITHOUT_PRIMARY_CONSTRUCTOR together.

Also fixed SUPERTYPE_INITIALIZED_WITHOUT_PRIMARY_CONSTRUCTOR incorrectly
repoted as warning instead of error.

compiler/fir/analysis-tests/testData/resolve/multifile/sealedStarImport.kt

@@ -5,7 +5,7 @@ package test
 sealed class Test {
     object O : Test()
 
-    class Extra(val x: Int): Test
+    class Extra(val x: Int): <!SUPERTYPE_NOT_INITIALIZED!>Test<!>
 }
 
 // FILE: main.kt