Split item bag into item metadata bag and item files bag

[HafeezOJ]

Is there an existing issue for this?

• I have searched the existing issues

Description

Currently, a bag containing files and metadata is generated for an item. With this feature, separated bags are generated for an item; an item metadata bag and a files bag. This will help to streamline updates to a bag and duplicate bag checks especially when there are minor updates to the bag.

Suggested Implementation

No response

[zoidy]

Implementation note regarding bag tags
If there are multiple bags,

• Bag-Count must be set to "X of Y"
• Bag-Group-Identifier must be set to External-Identifier. Refer to the spec for the format of External-Identifier (currently it's {id of item on figshare}-{version}-{first author firstname}-{first author lastname}-{hash} extracted from the bag name)

The only way a bag is valid when Bag-count is set and Bag-Group-Identifier is empty is if Bag-count "1 of 1" specifically. Otherwise it's invalid.