Context:
See parent task.

AT:

• there is new new endpoint on the definition resource that returns all available versions along with their versionTags given a definitionType and key
• versions are sorted descending by their numeric value
• the result can be filtered given a collection scope (e.g. based on the selected tenants some versions might not be available)
• the endpoint is documented in confluence

API-Suggestions:
GET /api/definition/:type:/:key:/versions

Query-Parameter:

filterByCollectionScope: "someCollectionId" // Optional. Only return versions that are available in the scope of the given collection (e.g. due to reduced tenant scope some versions might not be on the scope)

Response:

[
  {
     "version": "3",
     "versionTag": "fancy version tag"
  },
...
]