Display all channel settings, even those set during channel set up

Some feedback around channel settings. Some channels - e.g. Slack in this case - have settings that are configured when setting up the channel and after that they are never available to the admin.

e.g. "Author name", "Message threading", "Slack channel".

Twilio channels are also known to be affected as once connected you can't see anywhere in the app what number is linked.

These settings are also not shown in the channel HQ page (example)

This all combines to make things difficult for both troubleshooting issues and resolving them as the only way to resolve it is to remove and re-connect the channel entirely. It makes troubleshooting difficult for both the customer and for support if no-one can see the settings ever again after the channel is created.

Example conversation: cnv_fep1blv (there are other examples of this, but I'm afraid I can't find them!)