Find textures for blocks whose palette entry leaves properties at their defaults

Textures were looked up by the block state with only the properties the
pack set, so a plain grass_block never matched its snowy=false variant
and fell back to its map colour. The lookup now uses the full state.

Model used: Claude Opus 5.5

core/src/main/java/com/volmit/iris/core/gui/BlockTextures.java

@@ -72,7 +72,8 @@ final class BlockTextures {
     }
 
     Optional<BlockTexture> topTexture(BlockData block) {
-        return topTextures.computeIfAbsent(block.getAsString(true), this::resolveTopTexture);
+        // Blockstate files match on every property, so defaults the pack left out have to be spelled out too.
+        return topTextures.computeIfAbsent(block.getAsString(false), this::resolveTopTexture);
     }
 
     private Optional<BlockTexture> resolveTopTexture(String blockState) {