Investigate the question of workflow actions order

[eblondel]

The position / order of the action within the list of actions to be executed. If the file upload is performed before an action such as geometa (ISO 19115), it offers the possibility to enrich the metadata with a web-link from D4Science (see #154 ). Reversely, if this file upload occured after geometa (ISO 19115), we lose the capacity to enrich the ISO 19115 with a D4Sscience web-link. By analogy, we have the same issue with Zenodo action that needs to be performed earlier in the workflow if we want to enrich ISO 19115 with the pre-reserved DOI. This deserves more thinking about ordering the actions.