[Feature] select pocket dependencies on ppa creation (and or later update them)

A common reason for a PPA is to pre-build something complex before uploading it to the -devel release. But builds in -devel have proposed enabled by default.

The PPAs as created by ppa tools have only "default" like one you'd create on the Web-UI.
I'm assuming that developers not driving SRUs would appreciate a quick way to also enable proposed when creating their PPA.

The Web UI has:
Ubuntu dependencies:
 Basic (only released packages).
 Security (basic dependencies and important security updates).
 Default (security dependencies and recommended updates).
 Proposed (default dependencies and proposed updates).
 Backports (default dependencies and unsupported updates).

So it would be great to have this for users:

ppa create foo --dependencies [Basic|Security|Default|Proposed|Backports]

There is also a way to add custom dependencies, e.g. to other PPAs.
That imho is fine as a later addition not embedded to "create".
Or - for now - leaving that custom deps to the Web UI, but later on as a follow on item.