[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/testsWithStdLib/resolve/samOverloadsWithKtFunction.fir.kt

@@ -16,5 +16,5 @@ public class Foo {
 
 // FILE: 1.kt
 fun bar() {
-    Foo().<!AMBIGUITY!>test<!> {} <!INAPPLICABLE_CANDIDATE!>checkType<!> { <!UNRESOLVED_REFERENCE!>_<!><String>() }
-}
+    Foo().<!AMBIGUITY!>test<!> {} <!INAPPLICABLE_CANDIDATE!>checkType<!> { <!INAPPLICABLE_CANDIDATE!>_<!><String>() }
+}