[Feature Request] Remind user they're in offline mode.

[pmallot]

Is your feature request related to a problem? Please describe.
I just spent an embarrassingly long time trying to figure why TV-Rename would not run any scans. I tried all kinds of scans, I triple-checked settings, tried a different API, checked for a new version, anything I could think of. No success, it just wouldn't do it, not even a force refresh all.
Eventually I noticed a little check-mark next to a menu option I had never noticed before: "Offline Operation".
I have no idea how or when I must have mistakenly checked that, but it seems I had.
Unchecking it solved the issue.

Describe the solution you'd like
What I would expect is a reminder that "Offline Operation" is enabled whenever the user tries to run an operation that can not be run in offline mode.
Or maybe make all buttons corresponding to deactivated functionality greyed out and have a tooltip telling the user why.