[FEATURE] Integrations Dynamic Catalogs: JsonCatalogDataAdaptor

[Swiddis]

Is your feature request related to a problem?
While we've had CatalogDataAdaptors since 2.10, we only ever use it for reading directly from the local file system, which makes it impossible to upload integrations dynamically and difficult for outside contributors to develop integrations.

What solution would you like?
As part of ongoing efforts to support this dynamic upload user story, one step is adding a JsonCatalogDataAdaptor. This would define a flat file format which can be used to upload integrations with minimal implementation complexity, and lay the groundwork for later being able to read integrations from an index. It also would make more thorough testing of integrations possible by enabling easier mock.

What alternatives have you considered?
A ZipCatalogDataAdaptor was experimented with in a prototype, since it's easier for a user to zip an integration directly. This is more complex than a Json adaptor to implement, particularly because we need to serialize to a temporary file to get the data (there's an open issue in the Zip library we use to remove this constraint), and deserializing Zip generally brings more security considerations than Json. It will be explored more at a later date.

Do you have any additional context?
Some groundwork for Dynamic Catalogs was done with #1236. A larger meta-issue to bundle all this will be published eventually.