Replace "right bit" with single view and switch out models

[csmith]

At the moment each channel/server gets its own UI and we swap them in and out on change.

Things would be a lot easier if we just had one that got repopulated with the right data on switching.

Only concern is how quickly the richtext field can be cleared and filled with lots of lines. We could probably optimise it by adding the most recent lines first then slowly filling in the history.