Let users choose the name on poke

[Jokler]

Is your feature request related to a problem? Please describe.
Once multibot is implemented the bot might run out of names even though it still has identities available. Additionally some users might enjoy using a bot with a custom name more.

Describe the solution you'd like
When the master bot is poked the user can put the custom name into the poke message.

Describe alternatives you've considered
Generating names randomly are an option but the generated names might not be as good and users who want to have a custom name for their bots wouldn't be able to do so.
Random names could still be added separately down the line.