Unit image changes in various theater types

[obsidian14]

Unit image changes in various theater types

• Units on maps of different theater types can now change their models to the corresponding theater-specific models.
• The INI tags are shown below.

In rulesmd.ini:

[SOMEVEHICLE]                         ; VehicleType
Image.Temperate=                      ; VehicleType entry
Image.Snow=                           ; VehicleType entry
Image.Urban=                          ; VehicleType entry
Image.Desert=                         ; VehicleType entry
Image.NewUrban=                       ; VehicleType entry
Image.Lunar=                          ; VehicleType entry

[phoboscn-bot]

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This pull request has been mentioned on Phobos CN. There might be relevant details there:

致中文用户：
此拉取请求已在 Phobos CN 上被提及。那里可能有相关详细信息：

https://www.phoboscn.top/t/topic/692/1

[NetsuNegi]

You don't need to use Nullable in this PR for now

[NetsuNegi]

Suggested change

	Nullable<UnitTypeClass*> Image_Lunar;
	Valueable<UnitTypeClass*> Image_Lunar;

[NetsuNegi]

Suggested change

	Nullable<UnitTypeClass*> Image_NewUrban;
	Valueable<UnitTypeClass*> Image_NewUrban;

[NetsuNegi]

Suggested change

	Nullable<UnitTypeClass*> Image_Desert;
	Valueable<UnitTypeClass*> Image_Desert;

[NetsuNegi]

Suggested change

	Nullable<UnitTypeClass*> Image_Urban;
	Valueable<UnitTypeClass*> Image_Urban;

[NetsuNegi]

Suggested change

	Nullable<UnitTypeClass*> Image_Snow;
	Valueable<UnitTypeClass*> Image_Snow;

[NetsuNegi]

Suggested change

	Nullable<UnitTypeClass*> Image_Temperate;
	Valueable<UnitTypeClass*> Image_Temperate;

[github-actions]

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[TaranDahl]

Excluding aircraft seems unreasonable.
For vehicles, Ares has already dealt with the SHP. You only need to handle the voxel. The reading approach should align with the Ares pattern.
https://ares-developers.github.io/Ares-docs/new/alternatetheaterart.html
There are also issues with the implementation approach. The Theater does not switch mid‑game, so modifications should be made during asset loading to load different assets. This is different from damaged images. Damaged images and original images are used within the same game session, so loading both simultaneously is reasonable.