Add a `/move-conversation` feature, inspired by the Rust Community Discord

[jasonlessenich]

I guess this could be quite useful

[danthe1st]

Here are some things that need to be thought of:

• Should this feature only be accessible by moderators or also via a community-voting?
• If this should be allowed to use by non-moderators, the channels conversations should be movable to should be restricted (we don't want people to move conversations into #rules etc)
• If messages should be copied, a webhook should probably be used for avoiding rate-limits and preserving user names
• If messages should be copied, allowed_mentions need to be set to all copied messages.
• It should probably also be possible to let the bot create a thread and move the conversation in there.
• If a conversation is moved to a help channel, it should be reserved. Who should the help channel be reserved for?
• It should probably not be possible to move conversations into reserved/dormant help channels.
• How many messages should be moved when moving a conversation? How is this determined? Via message id? Specifying a number of messages to move? There should probably be a limit of messages to copy.

[liquiddevelopmentnet]

I think, due to confusion and safety, this feature should be only available to moderators.

[jasonlessenich]

Yeah, and I don't think it should copy the message. It's just a suggestion to move the ongoing conversation to another (thread) channel