[Feature Request] Guilds Tab in GUI

### Is your feature request related to a problem? Please describe.

GUI users or non-eval-command users sometimes run into issues knowing what servers their bot is in, and keeping track of which servers are currently using it.

### What is your ideal solution to the problem?

A GUI tab for guilds, titled `Servers` that contains information about the servers using the bot, their current music-related info, and some helpful buttons.

### How would this feature be used?

1. In the GUI, switch to the `Servers` tab
2. View a list of servers. Each server item will contain:
- Server Name
- Server Owner
- Approx. Member Count
- Now-Playing Song
- Number of Songs in the Queue
3. Each item will also contain buttons:
- Copy Server ID
- Stop Music
- Leave Server

### Additional Info

_No response_

### Checklist

- [X] I have checked [the documentation](https://jmusicbot.com/) to make sure this feature doesn't already exist
- [X] I have searched for [similar feature requests](https://github.com/jagrosh/MusicBot/labels/enhancement)
- [X] I have confirmed that my requests is **not** on the [list of things that will not be added](https://jmusicbot.com/things-that-wont-be-added)
- [X] I am running the latest version of the bot: 

No files, tests, or GUI entry points are named in the issue. Start by locating the existing GUI tab/navigation code, then define the data and actions needed for the Servers tab; done means listing each guild with its requested details and working Copy Server ID, Stop Music, and Leave Server buttons.

Written by the indexing model from the issue text.