Remove Data member from PropertyKind and make it non-Flags (#349)

Author: lahma

src/Esprima/Ast/PropertyKind.cs

@@ -1,14 +1,12 @@
 namespace Esprima.Ast;
 
-[Flags]
 public enum PropertyKind
 {
-    None = 0,
-    Data = 1,
-    Get = 2,
-    Set = 4,
-    Init = 8,
-    Constructor = 16,
-    Method = 32,
-    Property = 64
-};
+    None,
+    Get,
+    Set,
+    Init,
+    Constructor,
+    Method,
+    Property
+}