Tweak install scripts to enable clean reinstall on the same machine

Currently, in many KUD setup scripts, there is performed configuration, that is fine for newly created machine, but may be dangerous to use on already existing host (e.g. removing id_rsa key of running user). It also covers some applications and/or plugins being installed without prior checking if it's necessary (e.g. package is already installed).

Scope of this task is to refactor some installations script so that `aio.sh` could be run on already existing machine taking advantage of some steps already done where possible and not messing up existing configuration