Add custom maps

[MasterSon-git]

Try to integrate as new Theme Make compatible with "Paper Map all the way"

additionally add following maps:

• shaded relief map v2: https://steamcommunity.com/sharedfiles/filedetails/?id=3051232603
• navy paper mod: https://steamcommunity.com/sharedfiles/filedetails/?id=3082524396

one of these:

• victoria-2 style: https://steamcommunity.com/sharedfiles/filedetails/?id=2912060491
• clean map: https://steamcommunity.com/sharedfiles/filedetails/?id=2880218271

check: https://steamcommunity.com/sharedfiles/filedetails/?id=3052415455 this actually merges multiple maps

[MasterSon-git]

To-Do:

• add full map style from shaded relief map or navy paper mod
• community decision which one to take