dmg2mar script using hardcoded project names for paths

We can probably overide these env variables in the projects/release/dmg2mar script when invoking tools/dmg2mar

# If the application is not TorBrowser (for instance, TorMessenger)
# set the application name in the TOR_APPNAME_BUNDLE_OSX,
# TOR_APPNAME_DMGFILE and TOR_APPNAME_MARFILE environment variables
my $appname = $ENV{TOR_APPNAME_BUNDLE_OSX} // 'Tor Browser';
my $appname_dmg = $ENV{TOR_APPNAME_DMGFILE} // 'TorBrowser';
my $appname_mar = $ENV{TOR_APPNAME_MARFILE} // 'tor-browser';