[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/kt9430.fir.kt

@@ -12,5 +12,5 @@ class C: A() {
 }
 
 class D {
-    fun qux() { B().<!INAPPLICABLE_CANDIDATE!>foo<!>() }
-}
+    fun qux() { B().<!HIDDEN!>foo<!>() }
+}