Add property to add flow to Apps Blueprint

[aj-emerich]

Right now, the only way to include the connected flow into an Apps Blueprint is to include the flow yaml in the description or a link to it in the extend.description. This may not even be formatted appropriately or look very nice.

We should explore adding a sub-property to extend, like flowDependencies or the like, that can be more easily controlled, separate from the description, possibly with a collapse option, so it doesn't take up too much space on the blueprint page but is nonetheless available. Without it, the App is merely theoretical.

extend:
  flowDependencies:
    company.team.my_flow: |
      id: my_flow
      namespace: com.company.team
      ...
   company.other_flow: |
      ...