[FeatureFlags] Create API contracts for the feature Flag entity.

[Cartmanishere]

Schema for this entity is as follows:

- featureFlag
  + name [String] <Unique>
  + title [String]
  + id [String] <Unique>
  + created_at [Timestamp]
  + updated_at [Timestamp]
  + config [Object]
    - enabled [Boolean]
  + owner [String] (Unique identifier for user)
  + launched_at [Timestamp]

• Add the schema in the data-models repo.

These are the routes required for CRUD over this entity.

• Write Create featureFlag route.
• Write Update featureFlag route.
• Write Delete featureFlag route.
• Write a GET featureFlag route.
  • This returns all the feature flags for now.

The dashboard work is blocked on the create route and GET route, so we should finalize that part and the rest can be done async.