Check bagit validity for shipments

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Cases:

• [x] Check if bag
• [x] Check for valid bags
• [x] Create valid bag, if no bag or if bag needs update (arg + manifest invalid erc (substituter...)
• [x] Refuse shipping of invalid bags always
• [x] Give out responses, if bags are invalid, need update etc.
• [x] o2r web API updated
• [x] preserve bagit specific MD like Executable-Research-Compendium: True at update
• [x] create bagit specific MD when dir is not yet a bag (this will be added later)
• [x] use update md and update bag from bagit py

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also

• [x] update o2r web api for the new param

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included with 091cabb5645dd8b33c82ba468ce4f82a077bca5a