Tracking Porymap breaking changes

[GriffinRichards]

This issue is for tracking a few potential improvements that haven't been made because they would require changes to Porymap. This way if it's decided one breaking change should be made the rest can be easily referred to and piled on.

• object_event_graphics_info.h could be made more readable and less prone to errors from missing a field by using designated initializers (see Use designated initializers for object_event_graphics_info.h #1413). Porymap is currently unable to parse this.
• As of Document Pokénav #1550 files in graphics/pokenav are organized into subfolders, except for those read/written by Porymap whose paths would need to be updated. See Updates to region map for Porymap #1636
• Update event macro comments #1558 adds among other things constants for special warp ids. They can't be used in the dest_warp_id field because Porymap treats this as an int and won't properly handle macro names. See Rename special map constants, treat warp ids as strings #1755
• Additional constants in include/constants/heal_locations.h aren't preserved by Porymap, which prevents adding HEAL_LOCATION_NONE. See Add the HEAL_LOCATION_NONE constant #1671
• Not sure how worth changing it is, but the only reason data/tilesets.s is still in assembly is because Porymap expects it to be. Related: Convert map JSON data to C instead of asm #1736
• MAP_NONE is more accurately MAP_DYNAMIC, and MAP_UNDEFINED would be MAP_NONE. This could be updated, but Porymap currently hard codes "MAP_NONE" as "None" and expects any other MAP_ constant in a warp destination field to be a valid map, or it rejects the event. See Rename special map constants, treat warp ids as strings #1755

[GriffinRichards]

Reopening to track breaking changes in preparation for Porymap 6

• Fix defines in MAP_NUM and MAP_GROUP #2023 will update MAP_NUM/MAP_GROUP in a way that Porymap's Heal Location parsing doesn't currently handle.
• Related to the above, perhaps Heal Location data should be converted to JSON
• Porymap can stop writing some generated files (Stop needlessly writing to generated files. huderlem/porymap#556) after [Build System Rewrite] mapjson now takes output directory parameters. #1949 is merged.
• With the recent changes to support enums in assembly, I'm anticipating that Porymap will need to be able to deal with enums in some places that it currently expects #define. (Support for parsing enums huderlem/porymap#606)