[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/Protected.fir.kt

@@ -4,7 +4,7 @@ package k
 import JavaClass
 
 fun foo(javaClass: JavaClass) {
-    javaClass.<!INAPPLICABLE_CANDIDATE!>doSomething<!> {
+    javaClass.<!HIDDEN!>doSomething<!> {
         bar()
     }
 }