Expose a more detailed job status result - specifically, include upload status
alongside image status. Expand openapi.yml accordingly and add an UploadStatus
field to the OSBuildJobResult struct. At the moment, only represent the
"success" and "failure" states of UploadStatus - to differentiate between
"pending" and "running" would involve significant design decisions and should be
addressed in a separate commit.
Previously, baseurl was required in openapi.yaml. In order to add support
for metalink and mirrorlist repos as well, make all optional, since openapi
does not support mutually exclusive parameters. Instead, enforce this logic
in server.go, and if no repo has been specified, return a 400 bad request error.
