Enum deprecated syntax detection implemented and integrated into DeclarationsChecker.

A lot of tests was changed to refactor deprecated syntax. Six new tests were added to check deprecated syntax detection.
Diagnostic for "enum entry uses deprecated super constructor": constructor is highlighted
Diagnostic for "enum entry uses deprecated or no delimiter".
One warning removed.

compiler/testData/diagnostics/tests/when/ElseOnNullableEnum.kt

@@ -2,7 +2,7 @@
 
 // FILE: 1.kt
 
-enum class E { A B }
+enum class E { A, B }
 
 fun test(e: E?) = <!NO_ELSE_IN_WHEN!>when<!> (e) {
     E.A -> 1

compiler/testData/diagnostics/tests/when/ElseOnNullableEnumWithSmartCast.kt

@@ -1,4 +1,4 @@
-enum class E { A B }
+enum class E { A, B }
 
 fun foo(e: E, something: Any?): Int {
     if (something != null) return 0