feat: send, edit, and delete messages via ChannelWebhook?

[Taureon]

Describe your feature

It does not have methods for doing these three things, and they would be nice to have so you don't need to "manually" make http requests for these.

the apis could be like how discord does them for WebhookClients

[Kian-Abdalkhani]

Hey, I'd like to work on this if it's still available. I can add the 3 methods to ChannelWebhook with similar structure to how discord does them.

Let me know if there are any other specifics you'd like me to keep in mind.

[Taureon]

Hey, I'd like to work on this if it's still available. I can add the 3 methods to ChannelWebhook with similar structure to how discord does them.

Let me know if there are any other specifics you'd like me to keep in mind.

there are two relevant PRs to this one actually!
#142 which adds the sendMessage method since the api endpoint already exists, and stoatchat/stoatchat#682 which adds the ability to edit and delete websocket messages from websocket clients!

the second PR in /stoatchat is a draft because it needs someone else who's able to test these two endpoints, because i am unable to test them for whatever reason (already checked that issue with someone in the stoat dev server)

other than that, someone with write permissions needs to just check the PRs, which seems to be a larger issue across the organisation