make verbose a global state

make verbose a global state

This is part of the project 'stop the parameter rabbit hole madness'
and tries to make reading the firewall code a little bit easier.

Here we remove passing $verbose from 44 method signatures, while it
was used in 4 of those methods, a ration of 1/11 is simply not
acceptable for such a thing as a verbosity flag..

Remove it, and just make it a global variable with a setter for now.

Verbose is not modified in any API call, only in a Service
environment callablle by CLI, so we are save to do so.

If we decide to add some sort of firewall instance (i.e., a blessed
$self "object") with some state we could also move it there, but
making it global now doesn't hurt.

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>