[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/contracts/dsl/callUsualContractFunction.fir.kt

@@ -20,7 +20,7 @@ class SomeClass {
     }
 
     fun callMemberContractWithoutThis() {
-        <!INAPPLICABLE_CANDIDATE!>contract<!>()
+        <!NONE_APPLICABLE!>contract<!>()
     }
 
     fun callTopLevelSamePsiInMember() {