Minimize as move to new workspace

Because, we're discouraging from minimize and we're moving away from it, I propose a different way of "minimizing" or rather to make use of workspaces and automate using them:

* Clicking the icon on the dock will move the app with a "slide to right" animation to a new workspace at the end of all workspaces instead of minimizing, this will give a better feel of what's actually happening with a window
* Perhaps, a new button in the titlebar of a window that does that action, because it's performed quite often
* Because now that almost every app has it's own workspace, current Alt+Tab is rendered useless, because it switches only between apps on the current workspace, since every workspace will contain likely one window, Alt+Tab should then switch between all apps, not just current workspace.

Ongoing work here: https://github.com/elementary/gala/tree/minimize-to-new-workspace