Data type visibility and access (attachments vs signatures vs internal state)

[bjorntore]

We have identified three levels of data types:

• Attachments that are relevant to the end user and that are shown in the attachment list in the GUI.
• Signatures, payment information and other data types that TE will care about, but that there is no point in displaying in the attachment list.
• Internal state that only the app needs to see and know about. Like the state about the signees.

Find a good solution to this. Probably using some property on the data type. Must not be a breaking change.

Edit:
Setting "app:owned" as allowedContributers solves the most important thing: That the apps internal state objects can't be edited. What remains then is visibility. #1045 solves most of that.

Acceptance criteria:

• Can hide signatures and payment information from the attachments list.
• Can hide the signee state object from the attachment list.
• Normal attachments show up as before.
• Not a breaking change. Existing apps work 100% as before. The config is opt in.
• Tasks for Studio team have been created, to configure relevant data types with this automatically.