[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/classObjects/ClassObjectVisibility.fir.kt

@@ -2,7 +2,7 @@ package foo
 
 fun test() {
   A.d
-  A.Companion.<!INAPPLICABLE_CANDIDATE!>f<!>
+  A.Companion.f
   B.D
   CCC
   CCC.classObjectVar
@@ -27,4 +27,4 @@ class CCC() {
   private companion object {
     val classObjectVar = 3
   }
-}
+}