Improved Team chat

Customer user ID in support conversations, for Magpie staff

Magpie staff now see a customer's user ID beside their name on their messages in a support conversation.

Added the customer's user ID, in small grey text beside their name, to their messages in a Magpie support conversation in Team chat and in the Magpie app. Only Magpie staff see it. The customer does not, and no other conversation shows it.