map_data/geographical_region.txt Overhaul

[LT-Rascek]

The regions listed in geographical_region.txt require a serious overhaul; many duchies/regions are no longer valid and their associated events must be removed. Others will require significant refactoring to match the new map. This also ties into defining regions for GHW areas for new religions/faiths.

[LT-Rascek]

@loup99 This is (at least partially) alpha because it impacts how the Roman Reconquest CB will be defined. The remainder of it can be beta, however.

[LT-Rascek]

With Roman Reconquest CBs complete, this task is no longer alpha.