Add Notification for Tutors (fixes #14)

[AlphaKevin01]

No description provided.

[AlphaKevin01]

(#14)

[Rdeisenroth]

This will only work if the student joins via the /queue join command. Please also edit the voiceStateUpdateEvent.ts File to cover the voice channel join method.

Also i think it would help if the Tutors get notified when every student leaves and the queue is empty. Maybe a designated guild channel with restricted access for queue events would be a better option instead of notifying every active tutor individually, what do you think? Then we could also have a pinned message there that auto-updates whenever someone joins/leaves the queue.

[niklhut]

I think the idea with DMs is not that bad. This way a tutor only gets notified when they have an active session.
Even though a designated guild channel could be used as well, when only using a channel there is no guarantee an active tutor actually gets notified by this message.
In other words to get notified he would need to activate notifications for every message in this channel either permanently and the receive these updates when he is not in an active sessions as well, or turn the settings for notifications on and off every time he starts and ends his session. The latter would be rather tedious since he already calls the bot command, unless of course the bot could automatically handle the notification permissions, but I'm not sure if that is possible.
Another way to solve this would be that the bot always at mentions all active tutors in his status update messages, so there would be no need for notification permission changes, since you usually get notified for at mentions.

[niklhut]

Should create new role for currently active tutors.

Create notifications for tutors with active role in a separate channel. This means notifications when someone new joins the queue

[AlphaKevin01]

The /setqueueinfo command can be used to bind a text channel to a queue as a queue info channel. This text channel then informs all users with the role active_session about users joining the queue

[Rdeisenroth]

Oops, c2301d5 wasn't just linting, i also changed the role resolution to use the saved role ids instead of by name, as this would not work with custom role names.

[AlphaKevin01]

I have added a new service layer to manage the bot's business logic. In future, I think it would be logical to remove the actual logic from the commands and control it in the services classes in the service folder. This gives the project a better modularity and structure.

The example of the QueueInfoService clearly shows the layer division. What do you think of this approach?

Now to the new functionality:
with the command: /queueinfo set channel queue events
a given channel can be linked to a queue. This channel then logs the specified events. The events include: [join, leave, kick, next, tutor_session_start, tutor_session_stop].

The /queueinfo remove channel queue
command can be used to remove the channel as an infochannel.

[Rdeisenroth]

Small fixes still needed.

[Rdeisenroth]

LGTM