It validates arguments, creates a CampaignPlan and multiple CampaignJobs (one for each repo yielded by the CampaignTypes search query).
The single CampaignType that's currently implemented is "comby", which does search&replace across repositories.
What's in this PR already works: a plan is created, jobs are launched, executed and their Diff field is updated.
There are a few things missing that I want to address in follow-up PRs in order to make reviewing easier and to unblock @felixfbecker and @eseliger:
See comment belowThe diff produced by reading json-lines from the replacer service is not a valid multi-file diff. While it can be parsed again by diff.ParseMultiFile the produced []*diff.FileDiff only has a single element. That's enough to use the API for now, which is why I don't want it to block the merging of this PR. I will address this in a separate PR that also adds tests for comby (which right now only does a single HTTP request which we likely need to change)
CampaignPlans are not cleaned up yet. I already discussed this with @tsenart.
The CampaignPlan.status is still a dummy implementation.
