feat: support for Robot servers (#561)

Based on the Fork by Syself[0] and the Design Doc[1].

[0] https://github.com/syself/hetzner-cloud-controller-manager
[1] https://github.com/hetznercloud/hcloud-cloud-controller-manager/issues/523#issue-1925577588



This ports most features of the fork while refactoring them to match
our coding style and the improvements I made in preparation for this.

Closes #525 #526 #527

---------

Co-authored-by: janiskemper <janis.kemper@syself.com>
Co-authored-by: Mawe Sprenger <mawe.sprenger@denkweit.de>
Co-authored-by: Thomas Guettler <thomas.guettler@syself.com>
Co-authored-by: Anurag <contact.anurag7@gmail.com>
Co-authored-by: batistein <sven.batista-steinbach@syself.com>