Feature request: Allow students to change their field of study role

[xvanick1]

Description of the feature

Allow users to change their assigned field of study role to a different one even through they don't officially study that desired field at the moment.

Students sometimes want to check the content in the private rooms of another field to ask questions. Alternatively, they are changing field of study and the proccess is taking too long. In both cases they have to contact admins to update their role.

Upon users request, bot would show list of buttons, where every button represents one field role. According to users choice, bot will assign to the user a role of the desired field and unassing the former field.

User can have only one field role assigned at a time.

No changes in database are needed.

Related links

Inspiration for the implementation can be found here and in the /channelmanagement slash command