When manually creating a track, automatically give it a default name.

When manually creating a track, automatically give it a default name.

Now one can just click OK, and get on with creating the track (without needing to type anything).
Of course, one can change the suggested name or rename the track after creation via the layers panel features.

Signed-off-by: Guilhem Bonnefille <guilhem.bonnefille@gmail.com>