[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/scopes/protectedVisibility/syntheticPropertyExtensions.fir.kt

@@ -40,6 +40,6 @@ class B : A() {
 }
 
 fun baz(a: A) {
-    a.<!INAPPLICABLE_CANDIDATE!>foo<!>
+    a.<!HIDDEN!>foo<!>
     a.bar = a.bar + ""
 }