Drop old enum syntax. Comma / semicolon are now a syntactic part of enum entry.

Comma must present now between enum entries, semicolon between last entry & first member, constructor calls must be without colons / specifiers.
A swarm of tests fixed accordingly.

compiler/testData/psi/EnumEntryCommaMember.kt

@@ -0,0 +1,5 @@
+enum class My {
+    FIRST,
+
+    fun foo() {}
+}