Add an option to exit the Sigrid CI script while waiting for analysis results

[erik-blokland]

When not using --publishonly, Sigrid CI provides feedback on the changes present in uploaded code within the CI environment itself. Currently, the Sigrid CI script will wait for results before continuing.

Providing some way to exit the CI script and return later in the pipeline to retrieve the results would allow CI resources to be used more efficiently on systems with a longer analysis time.