Implement Webhook Message Edit/Delete

[Daniel-Worrall]

Relevant docs
https://discord.com/developers/docs/resources/webhook#edit-webhook-message
https://discord.com/developers/docs/resources/webhook#delete-webhook-message

[GeopJr]

#4 adds them: https://github.com/shardlab/discordcr/pull/4/files#diff-6d61ab1e72964d9c4ea6a74313f1025c1741dbad344401b0c3c3fb26bab3885bR1830-R1862

(because they are being used by interactions https://github.com/shardlab/discordcr/pull/4/files#diff-6d61ab1e72964d9c4ea6a74313f1025c1741dbad344401b0c3c3fb26bab3885bR2033-R2068)

[Daniel-Worrall]

Welp. I'm a blind person

[PixeLInc]

This will be closed by #31 once that is merged.