Use Wish from Charm as a boilerplate for SSH app

[LeoColomb]

For my next contribution, I'm considering refactoring some parts of the SSH server/app.
The main goals:

• Reduce the size of IngreSsh SSH server/app code base, to ease the maintenance as much as possible.
• Embrace best practices & best UX for this kind of app, i.e., lower surface for any opinionated tweaks.

Why Wish?

• Current app already uses most of the Charm modules that Wish depends on;
• Wish is the perfect wrapper for this kind of app;
• The technical dept will delegate responsibility to Charm's implementation;
• Wishlist app provides a reference on how to use it.

As it might be quite an effort, few checks before I actually start:

• Does that sound interesting to you?
• After all the noises and contributions I made these last weeks, should I slow down, or can I keep it up?

[Kooper]

@LeoColomb, I think we may go this direction.
I have no prior experience with Wish, however, your reasoning makes sense - if we're able to achieve a more compact implementation this will be fine. Streamlining UX and unlocking new features will also be great.

As for the development pace - it's up to you. I'm OK with reviewing changesets once in a day or two now 🤝