feat(api): api queue routes / notifier

Implements the following features:

• /api/queue/packages route: returns a JSON object with information about all packages currently queued for building
• /api/queue/stats: returns a JSON object containing information about the queue status, like waiting and active count
• Notifier class, which is used to send notifications to certain targets. Currently implemented is sending to Telegram chats
• Changes the pipeline config to no longer try building any container from MRs
• Changes date outputs to be much easier to read (eg. 26/05/2024, 11:20:49 UTC)
• Misc changes, like using /usr/bin/env instead of /bin/bash for Nix friendly scripts