refactor: prefer systemd sockets over socat

- Document preferred method for socket use depending on use case;
- Fix Github web-flow key;
- Standardize naming of services;
- Use sys-ssh in ansible formula;
- Start services conditionally with Qubes Service and evaluated by
  systemd ConditionPathExists= instead of installing on a per qube basis
  with rc.local scripts;
- Change Qusal services to "qusal-" prefix instead of "qubes-" prefix.

Fixes: https://github.com/ben-grande/qusal/issues/80
Fixes: https://github.com/ben-grande/qusal/issues/79

salt/sys-ssh/init.top

@@ -10,5 +10,3 @@ base:
     - sys-ssh.create
   'tpl-sys-ssh':
     - sys-ssh.install
-  'sys-ssh':
-    - sys-ssh.configure