[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/tests-spec/testData/diagnostics/notLinked/dfa/neg/30.fir.kt

@@ -32,6 +32,6 @@ class Case5(val y: Any?): ClassWithCostructorParam(y as Interface1), Interface1
 fun case_6(a: Int?) = object : ClassWithCostructorParam(a!!) {
     fun run() = a.<!INAPPLICABLE_CANDIDATE!>toShort<!>()
     init {
-        <!AMBIGUITY!>println<!>(a.<!INAPPLICABLE_CANDIDATE!>toShort<!>())
+        println(a.<!INAPPLICABLE_CANDIDATE!>toShort<!>())
     }
 }