Update GitLab CI API `Builds` resource to be `Jobs`
As part of the larger effort to change usage of Builds to either Pipelines or Jobs, we should also update the GitLab CI API. The main location that contains references to builds is the Builds API.
These API endpoints should be updated to be named Jobs, since they deal with a specific job of a pipeline. Since this is a breaking change, we should ensure these API's continue to work as-is. The name change to jobs should take effect with v4.