EAM API: Regions for App definitions

[gainsley]

Problem description

EdgeXR's App definitions are stored per region, to allow for data sovereignty for data restricted to a specific region. The NBI API specifies regions for Zones and AppInstances, but not for Apps. We would like to propose scoping App definitions to regions as well.

Possible evolution

Add a region parameter to the App APIs, the same as the Zone and AppInstance APIs.

Alternative solution

Make the region parameter for App APIs optional, allowing for either global or regional App definitions. This makes the solution more complex but allows for specific App definitions to conform to data sovereignty requirements, while allowing for other App definitions without such requirements to remain global and more easily managed.

Additional context