[booth] `pcs booth ticket add` shall be accompanied with native validation

Pcs currently allows for invalid configuration for booth to be
generated, such as when (under simplification) `expire` period
is lower than or equal to 110 (see `boothd(8)`), resulting in:

> Jan 09 17:10:21 virt-184 booth: [13184]: error: TICKET02: total amount of time to retry sending packets cannot exceed renewal frequency (5000*(10+1) >= 50000)
> Jan 09 17:10:21 virt-184 booth: [13184]: error: in config file line 8

The suggested way to address that on `pcs` side:

1. working generated contents of configuration file is output
to a side, temporary and possibly persistence-unbacked location
(`/run/pcs/booth/virt-184/booth-booth.conf` for instance)

2. actual validation by booth is performed like this:

```
booth status -c /run/pcs/booth/virt-184/booth-booth-FDs3k.conf
```

3. the only complication possible -- the above may be launched on
node that is not currently in possesion of cluster-wide
`booth-booth-ip` resource (or equivalent), hence this would be
shown as an error, resulting in exit status of `1`:

```
Jan 09 17:43:17 virt-184 booth: [16750]: error: Cannot find myself in the configuration.
```

to workaround this, a cheap trick -- inject localhost address(es) --
could be applied; note that it's important to inject it in a way
that the resulting number of the actors will be odd, so e.g.,
add:

```
site = 127.0.0.1
site = 127.0.0.2
```

of course, this addition would need to be undone again when
the configuration as such passes, removing the working file
(`/run/pcs/booth/virt-184/booth-booth-FDs3k.conf`) behind