If we find that the settings file doesn't exist, or is empty, then let's quick
delete the state file as well. If the user does have a state file, and not a
settings, then they probably tried to reset their settings. It might have data
in it that was only relevant for a previous iteration of the settings file. If
we don't, we'll load the old state and ignore all dynamic profiles (for
example)!
We'll remove all of the data in the `ApplicationState` object and reset it to
the defaults.
This will delete the state file!
That's the sure-fire way to make sure the data doesn't come back. If we leave
it untouched, then when we go to write the file back out, we'll first re-read
it's contents and try to overlay our new state. However, nullopts won't remove
keys from the JSON, so we'll end up with the original state in the file.
* [x] Closes#11119
* [x] Tested on a cold launch of the Terminal with an existing `state.json`
and an empty `settings.json`
* [x] Tested a hot-reload of deleting the `settings.json`