CMS - Add dialogs for api errors

[ComputerGhost]

Auth is the most important. Instead of simply refreshing the window, pop something up saying the session is expired and let the user click to open a new window that will refresh it.

Also we need to handle 403 forbidden and of course all of the 5xx errors. Probably in a simpler way with a simple text popup. Or put these inside the action buttons that are hit if hit within an action button. That would be useful too.

[ComputerGhost]

The scope may need bent after the recent refactor and changes of tech, but the sense of this issue is still applicable.