flatpak: update files following names change + Python 3 update: - `build_manifest.py` has been fixed to work with recent SàT/Libervia - filenames/scripts have been udpated to reflect project name change - installation now uses `requirements.txt` when dev version is requested - there are now 3 types of commands wrapper: * `libervia_wrapper.py` uses `pb` bridge, starts backend before frontend, and stops it when frontend is stopped. It's used by `Libervia Desktop` (Cagou) * `libervia_wrapper-dbus.py` uses `dbus` bridge, starts backend before frontend, and stops it when frontend is stopped. It's used for `Libervia TUI` (Primitivus) * `libervia_wrapper-dbus.py` uses `dbus` bridge, starts backend if necessary and doesn't stop it (to avoid waiting for backend start next time). It's used by `Libervia CLI` (jp).

$ORIGIN 0.0.127.in-addr.arpa.
$TTL 1D
@     IN SOA  <hostname>.<domain>. <hostname>.<domain>. (
              <date>     ; serial
              28800      ; refresh (8 hours)
              14400      ; retry (4 hours)
              2419200    ; expire (4 weeks)
              86400      ; minimum (1 day)
              )

              NS      <hostname>.<domain>.
1             PTR     <hostname>.<domain>.