Slash command support

[jchristgit]

Per discussion in #1 with @Bentheburrito.

I think Slash Commands are different enough to warrant their own behaviour imo. I have a rudimentary slash command handler on another bot that I could clean up and use as a starting point? Also, should I open a separate issue for further discussion?

My current idea:

• Implement a new Nosedrum.SlashCommand behaviour.
• Implement an interaction handler (possibly some kind of merge between Nosedrum.Invoker and Nosedrum.Storage, since the Invoker is less useful here) to dispatch, store and manage commands.

[Bentheburrito]

I noticed Discord recently changed terminology to "Application Commands" https://discord.com/developers/docs/interactions/application-commands - which include User/Message commands in addition to Slash Commands. Are these two new types of commands something you see Nosedrum supporting?

[jchristgit]

Hmm, from a quick glance over it, it looks like these are pretty much just built on top of the existing slash commands? Interesting, I haven't seen these before. Yeah, I think we should possibly name it something like Nosedrum.ApplicationCommand then, and integrate with that

[Bentheburrito]

Cool! I'm happy to get started on this then :)

[jchristgit]

Awesome, I'll assign you then, Thank you!