CDC/Metadata workflow adjustments

[MPDLRanger]

• [ ] Remove CDC from library
• [ ] Remove archive-metadata.md from library
• [ ] Remove CDC Howto
• [ ] Add metadata form (see #422 ) to Archive workflow (to popup window)
• [ ] Add metadata form (see #422 ) to DOI workflow (to popup window)
• [ ] Add metadata button to library (next to "Archive")
• [ ] Successfully metadata creates CDC (not saved on library anymore), shown on library overview page
• [ ] Create overview page, once CDC is created (similar to when it's created after archiving or DOI creation), in case there isn't a library details page already
• [ ] Add "Change metadata" button to library details page
• [ ] Note: bloxberg additional data is unrelated to this metadata, but the form can be reused