Chore: Review permissions and naming around access to application

Currently there is no concept of application level permissions within the codebase.

If a user has permission to create/view/update/delete an instance, it's assumed they have exactly the same permission level for applications.

If in the future, users should only have access to some instances within an application; or only have view permissions at application level but edit at instance level, application level permissions will need to be introduced.