[FIR] Improve diagnostic reporting & don't use error symbol for candidate if possible

Also introduce few new diagnostics:
- NONE_APPLICABLE more many inapplicable candidates
- HIDDEN for visible candidates

compiler/testData/diagnostics/tests/syntheticExtensions/samAdapters/Private.fir.kt

@@ -1,10 +1,10 @@
 // !WITH_NEW_INFERENCE
 // FILE: KotlinFile.kt
 fun foo(javaClass: JavaClass) {
-    javaClass.<!INAPPLICABLE_CANDIDATE!>doSomething<!> { }
+    javaClass.<!HIDDEN!>doSomething<!> { }
 }
 
 // FILE: JavaClass.java
 public class JavaClass {
     private void doSomething(Runnable runnable) { runnable.run(); }
-}
+}