oaiharvester: upload module added

From about here the function is almost identical to `workflows.tasks.submission.send_robotupload()` used in the deposit workflow. It would be more maintainable if we would factor out the identical parts into a generic function that takes care of sending the upload.

#### Suggestion

1. Move the common parts (factored out from this function and the one used in submissions) into `utils.robotupload.py` that exist already

2. Import and use the function from (1) in two new functions: one for deposit (sip stuff) and one for the oaiharvest stuff (similar to what you did with #109)