[feature] Add flag to run and exit after checking all changes

[nebula-it]

Version and OS
docker

Is your feature request related to a problem? Please describe.
changedetection consumes resources even on idle and for our use case running it once every 24 hours is enough.

Describe the solution you'd like
Allow option to execute change detection, check changes for all configured items and then exit

Describe the use-case and give concrete real-world examples
As mentioned above, even at idle change detection eats up CPU. And since its going to be idle for 99% of the time it'd be great if it was possible to start this process once where it'd check everything and then exit. With that it can be easily run as cron (in my case kubernetes cron job)

Additional context
Add any other context or screenshots about the feature request here.

[dgtlmoon]

Lets try to work out the main problem before adding more functionality

"As mentioned above, even at idle change detection eats up CPU. "

can you give any evidence?

can you tell anything at all about your environment? how many watches? any data at all?