Allow setting of `--push-option` on Campaigns

Created by: adam-moss

Feature request description

The ability to set git --push-option on campaigns, for example to set ci.skip

Is your feature request related to a problem? If so, please describe.

When running a campaign it may not be necessary to run CI immediately as part of it. For example a campaign that provides information on something that needs to change "remove XXX from YYY, ZZZ" but doesn't provide a concrete merge request - i.e. it requires additional commits to the MR to be successful.

Describe alternatives you've considered.

Including ci.skip in the commit message title, but this is a little messy.