Better "Apply to device" flow

[dlewis2017]

I spent too long trying to figure out why my app with a library I was using couldn't read from the battery service only to find out it didn't have anything to do with their code but saving configurations in the Connect for Desktop BLE app.

When pre-loading config, maybe even when adding new services/characteristics, it seems you need to be very specific with the order in which you save and apply things.

1. Add service, save, apply, popup to confirm.
2. When loading config: Clear first (?), apply, popup to confirm, load setup, apply, popup to confirm.

I wasn't doing things in this exact order so I couldn't read or write. It'd be great if pressing "Apply to device" does all of that in the background.

Repro steps would be:

1. Connect to nRF dongle
2. Add services and characteristics
3. "Save setup"
4. Restart
5. Connect to dongle
6. Load Setup
7. Click "Apply to device"
8. Test

For more system details see this post:
woodemi/quick_blue#133