Look into making protos package in defang repo its own submodule

[nullfunc]

Look into making the defang protos package it's own submodule to be build and imported into defang and defang-mvp repos.
Both repos have a dependency on the protos package but at current it's built as part of the defang repo. Protos changes are created as a separate PR with only protos changes. This suggests separating out the package into it's own repo which will also allow us to tag release versions.