Add slack integration to do ICS 20 transfers

[colin-axner]

Add the command:
/transfer <chain-id> <emoji> <receive-address>

This should send the emoji from the users account to the corresponding chain using the receive address

IBC does not have a canonical understanding of what means, the more appropriate usage would be to specify the port/channel to use. This is an acceptable implementation. I assume slackbot is being used with a pooltoy instance with a relatively low amount of connections, thus I think it might be useful to do a light weight implementation of the chain naming service which allows the admins to add to the internal mapping of chain-id -> channel/port