feat: use long-polling to update the UI based on snapd's state

[d-loose]

Automatically updates the UI when

• the prompting feature is toggled externally
• prompting rules change

This also includes some retry logic to gracefully handle snapd errors while it's restarting when the feature flag is toggled

Screencast from 2024-08-23 13-58-16.webm

The UI change is a bit delayed when the feature is toggled externally, I'll see if I can add a loading state or at least disable the toggle button for that case.

Added a waitingForSnapd state

Screencast from 2024-08-23 14-31-18.webm

UDENG-3790 UDENG-4077

[d-loose]

For testing, a snap is building here. It'd be great if someone could test it in a VM with snapd from edge and the prompting-client installed. The security center should handle the following scenarios without any errors:

• enabling/disabling prompting using the UI
• enabling/disabling prompting via the CLI while the UI is running - the UI should update accordingly
• when a rule is modified/added externally (e.g. by replying to a prompt) the UI should update accordingly

[matthew-hagemann]

I found that if you cancel out of the sudo password prompt when toggling prompting, the option remains off until you restart the security center:

Screencast from 2024-08-27 13-42-07.webm

[d-loose]

I found that if you cancel out of the sudo password prompt when toggling prompting, the option remains off until you restart the security center:

Very good catch, thanks a lot! I'll need to handle that case explicitly