Codepipeline: Implement put_job_success_result & put_job_failure_result

[sslogar]

Per the implemented services page, put_job_success_result and put_job_failure_result are not implemented for the code pipeline service.

I would like to add these methods to the mocked service.

[Mide69]

@bblommers I'd like to pick this one up too, it builds on #10191 since job polling only makes sense once a pipeline execution exists.

Plan: add a Job store to CodePipelineBackend, keyed by jobId, created when a pipeline execution's action needs a custom job worker. put_job_success_result and put_job_failure_result will just update the stored job's status to Succeeded/Failed.

I'll hold off starting until #10191 lands since it's the prerequisite. Could this be assigned to me in the meantime?

[sslogar]

@Mide69 Thank you for taking a look at this. If it's ok, I'd like to be assigned to this one since I'm trying to contribute a bit more to open source!

[Mide69]

@sslogar No worries my friend, all yours.