[Feature Request] Add save(grap) command

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

It is not a problem.

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

Add the "grap" command. The bot sends the current music in MP.
Like this :

### How would this feature be used?

**1.** [prefix]grap (save or steal.....)
**2.** The bot sends the current music in MP with the link.

### 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: 

Start by reviewing the command-handling code and the closed pull request #579, then compare them with the requested [prefix]grap behavior. Done means the bot sends the current music as an MP with its link, as described in the issue.

Written by the indexing model from the issue text.