Add possibilty to setup custom inbox category

[Akinator31]

Currently, when a user contacts the bot to open a ticket, the ticket arrives in the “Inbox” category specified in the bot configuration.

The goal would be to allow staff to specify ticket categories and give users who want to create a ticket the option to categorize their request themselves. If the user does not make a selection within 5 minutes (this setting can be adjusted), the ticket will automatically be placed in the default “Inbox” category. However, if the user selects a specific category, the ticket will be opened in the correct category.

Imagine you are using Rustmail for a game server. You will be able to configure categories so that your players can categorize their requests themselves. For example, you can configure a “Connection Problem” category that players can select when they send a message to the bot, and the ticket will be placed in the correct category.