[VISUAL] $seamless_scale can't be used with $blendmodulatetexture

[Yankumo-Koishi]

When using $seamless_scale with $blendmodulatetexture, the textures on the Z-Axis doesn't render correctly
This is a Mapbase-Only bug because stock shaders works fine for them

(I can't upload example images for some reasons)
https://media.discordapp.net/attachments/550382172050030602/1422486367501553684/image.png?ex=68dd81ea&is=68dc306a&hm=83d4cae8dc600edaeee082470705e8539050a659fcfdd62957938fcfd6657b81&=&format=webp&quality=lossless&width=987&height=552

[WhiteRedDragons]

For Reference this happens because in the Shader it uses the BaseTexture Coordinates
Which on Seamless Mapping are used as a float3 not a float2
See here
Stock Shader passes the BaseUV via the free slots on LightmapTexCoord
This still happens on the Mapbase LMG Vertex Shader
but it's not being applied. Here is the Stock Shader using the free lightmap texcoord space on the pixel shader
The intention here was probably that the blendmodulate should also be mapped via seamless texture coordinates.
Frankly this would have been discovered sooner if warnings were on, this is an implicit truncation of a vector type ( float3 -> float2 )

Two options here

1. Use the lightmap coord.zw like the stock shader ( making the BlendModulateTexture not seamlessly mapped )
2. Apply Seamless Mapping when Seamless Mapping to the BlendModulateTexture