Submit metadata to EGA and add EGA identifiers to objects

[blankdots]

Description

We need to make use of: https://ega-archive.org/submission/programmatic_submissions/submitting-metadata
For FEGA submission we need to add a key about it in the folder e.g. fega (boolean) that will classify that folder/submission as a submission to FEGA

Additional Info: https://ega-archive.org/submission/programmatic-submissions

DoD (Definition of Done)

introduce a new API endpoint to trigger a submission to fega

Testing

Integration testing, we need to mock the CEGA API

[csc-felipe]

This could be implemented as part of the EGA workflow, so related to #362.

[blankdots]

i think we should not cluster too many in the workflow issue #362, as it will require adhering to https://ega-archive.org/submission/programmatic_submissions/json-message-format which would imply some mapping from our db to this format.

[csc-felipe]

That makes sense.