[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/visibility.fir.kt

@@ -40,8 +40,8 @@ class B {
 }
 
 fun test3(a: A) {
-    a.<!INAPPLICABLE_CANDIDATE!>v<!> //todo .bMethod()
-    a.<!INAPPLICABLE_CANDIDATE!>f<!>(0, 1) //todo .bMethod()
+    a.<!HIDDEN!>v<!> //todo .bMethod()
+    a.<!HIDDEN!>f<!>(0, 1) //todo .bMethod()
 }
 
 interface T
@@ -54,7 +54,7 @@ open class C : T {
 }
 
 fun test4(c: C) {
-    c.<!INAPPLICABLE_CANDIDATE, INAPPLICABLE_CANDIDATE!>i<!><!UNRESOLVED_REFERENCE!>++<!>
+    c.<!HIDDEN, HIDDEN!>i<!>++
 }
 
 class D : C() {
@@ -78,7 +78,7 @@ class F : C() {
 
 class G : T {
     fun test8(c: C) {
-        doSmth(c.<!INAPPLICABLE_CANDIDATE!>i<!>)
+        doSmth(c.<!HIDDEN!>i<!>)
     }
 }
 
@@ -91,5 +91,5 @@ import test_visibility.*
 
 fun test() {
     internal_fun()
-    <!INAPPLICABLE_CANDIDATE!>private_fun<!>()
+    <!HIDDEN!>private_fun<!>()
 }