[Enhancement] Import/export V1 common color palette in ScummRP

[dwatteau]

https://www.jestarjokin.net/apps/scummimg/ (a very nice tool) says:

[for V1 resources] Note that scummrp also does not output the common colour palette; you can use the included v1col_extract and v1col_insert tools to get this information.

Here are the scripts (MIT too):

https://bitbucket.org/jestar_jokin/scumm-image-encoder/src/master/src/v1col_extract.py
https://bitbucket.org/jestar_jokin/scumm-image-encoder/src/master/src/v1col_insert.py

We could probably add this inside ScummRP.