Add dropdown to /inventory command for quick navigation (#365)

- Add ability to handle dropdown menus with the bot
- Add a dropdown to the inventoryhelper
- Add handler for the dropdown to navigate to that page

#344

Reviewed-on: #365
Reviewed-by: VylpesTester <tester@vylpes.com>
Co-authored-by: Ethan Lane <ethan@vylpes.com>
Co-committed-by: Ethan Lane <ethan@vylpes.com>

src/contracts/StringDropdownEventItem.ts

@@ -0,0 +1,10 @@
+import {Environment} from "../constants/Environment";
+import {StringDropdownEvent} from "../type/stringDropdownEvent";
+
+interface StringDropdownEventItem {
+    DropdownId: string,
+    Event: StringDropdownEvent,
+    Environment: Environment,
+}
+
+export default StringDropdownEventItem;