Management for Items/Collections (Transaction Extensions)

[m-mohr]

Implement creating/editing/deleting Items/Collections vie the Transaction Extension and the Collection Transaction Extension.

Other relevant links:

• Determine whether someone is allowed to use transactions opengeospatial/ogcapi-features#1005
• How to detect whether someone has the required privileges? stac-api-extensions/transaction#15
• https://github.com/stac-utils/stac-fields
• https://github.com/developmentseed/stac-manager

Implement this in two steps:

1. API interactions and editing only via a JSON editor (in 3.4 or 3.5)
2. Implement a second visual editing mode that supports creating the JSON (with help of stac-fields) (after Vue 3 migration in 4.x?)

Potentially implement #321 to allow external tools to be used instead of the STAC Browser implementations.