Implemented room permission types

Done in preperations for rooms,
and the ability to edit rooms.

Will later be used to hide/show certain elements,
when the user does not meet the criteria
(permissions / admin / owner)

lib/backend/permissions.dart

@@ -0,0 +1,41 @@
+// implementation of permission types
+// according to the server permissions.ts
+// https://codeberg.org/outbag/server/src/branch/dev/src/server/permissions.ts
+
+// same as javascript 0b prefix
+// pronounced o-b
+int oB(String binary) {
+    return int.parse(binary, radix: 2);
+}
+
+class ServerPermission {}
+
+class RoomPermission {
+  static int get addArticles {
+    return oB("0000001");
+  }
+
+  static int get removeArticles {
+    return oB("0000010");
+  }
+
+  static int get listGroupsItems {
+    return oB("0000100");
+  }
+
+  static int get changeMeta {
+    return oB("0001000");
+  }
+
+  static int get ota {
+    return oB("0010000");
+  }
+
+  static int get changeAdmin {
+    return oB("0100000");
+  }
+
+  static int get manageMembers {
+    return oB("1000000");
+  }
+}