[TD] Update diagnostics test data due to new test runners

Update includes:
- Changing syntax of `OI/`NI` tags from `<!NI;TAG!>` to `<!TAG{NI}!>`
- Fix some incorrect directives
- Change order of diagnostics in some places
- Remove ignored diagnostics from FIR test data (previously `DIAGNOSTICS` didn't work)
- Update FIR dumps in some places and add `FIR_IDENTICAL` if needed
- Replace all JAVAC_SKIP with SKIP_JAVAC directive

compiler/testData/diagnostics/tests/nullabilityAndSmartCasts/AssertNotNull.kt

@@ -35,5 +35,5 @@ fun main() {
     }
 
     val <!UNUSED_VARIABLE!>f<!> : String = <!TYPE_MISMATCH!>a<!><!UNNECESSARY_NOT_NULL_ASSERTION!>!!<!>
-    checkSubtype<String>(<!NI;TYPE_MISMATCH!><!OI;TYPE_MISMATCH!>a<!><!UNNECESSARY_NOT_NULL_ASSERTION!>!!<!><!>)
-}
+    checkSubtype<String>(<!TYPE_MISMATCH{NI}!><!TYPE_MISMATCH{OI}!>a<!><!UNNECESSARY_NOT_NULL_ASSERTION!>!!<!><!>)
+}