Added patroni prometheus exporter and scraping through nginx and certs with little trick in the /etc/hosts

Modified the DNS scraping jobs to find their queries in seperate files. First tested on hellsing2 and all seems fine, everything is up in the targets.

Update/Correction of bugs to make the frr exporter functional from a call of the frr/haproxy roles. Changed the blackbox exporter not to scrape meru3.

Several minor changes for Prometheus, Blackbox Exporter variables and pct role avoiding writing into the Prometheus files which don't exist (DNS SRV)

Implementing Blackbox Exporter for Faster. Many changes and bug corrections in different submodules. Next issue to solve with knsupdate in the task dns TXT entries

Added a conditional addition of the ipv6 to /etc/hosts of both hellsing Prometheus servers depending on their service vrf interface

Latest changes to the roles for Prometheus exporter working with fail2ban. Tested on Debian.

See merge request !3