FlowEditor: Creating collections dynamically

[AkhileshNegi]

Is your feature request related to a problem? Please describe.
Right now, one has to create a collection on a separate screen. Once it's made, one can then use it in the flow editor.

Describe the solution you'd like
If we could create collections on the fly, like we do with the contact field, it would make things a lot easier. Here's how the contact field is created: