Draft a generic approach for source selection by types

[eblondel]

source data (metadata description, contacts) can be handled in different content management systems:

• db tables (database table)
• remote files (cloud): including gsheet (google spreadsheet) or potentially others
• local files: CSV, or other formats
  The purpose here is to draft a Dublin Core based workflow with a generic way to handle sources.
  For top flexibility, we may have several sources, at least metadata and contacts, with different types and formats of sources. By format, it can be a file format, a protocol, or api