Add support for uploading app files + databases

[martin-helmich]

This PR adds support for a mw app upload and a mw database mysql import command. Both of these are useful for offering a quick way to publish a development environment onto a server (most prominently, for using ddev push).

⚠️ It needs to be stressed that this is a development tool, and not a suitable substitute for a production-ready deployment solution.

[LukasFritzeDev]

Look good