[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/declarationChecks/MultiDeclarationErrors.fir.kt

@@ -18,4 +18,4 @@ fun test(mc1: MyClass, mc2: MyClass2) {
     use(a, b, c)
 }
 
-fun use(vararg a: Any?) = a
+fun use(vararg a: Any?) = a