Changed AEGlassMaterial to Materials

Preparation in case we need more to support custom non solid, non
opaque, or similar blocks.
Removed custom fullSize/opaque blocks in favour of Material

src/main/java/appeng/decorative/solid/QuartzGlassBlock.java

@@ -23,7 +23,7 @@ import net.minecraft.block.BlockState;
 import net.minecraft.block.material.Material;
 import net.minecraft.util.Direction;
 
-import appeng.helpers.AEGlassMaterial;
+import appeng.helpers.AEMaterials;
 
 public class QuartzGlassBlock extends AbstractGlassBlock {
 
@@ -34,7 +34,7 @@ public class QuartzGlassBlock extends AbstractGlassBlock {
     @Override
     public boolean isSideInvisible(BlockState state, BlockState adjacentBlockState, Direction side) {
         final Material mat = adjacentBlockState.getMaterial();
-        if (mat == Material.GLASS || mat == AEGlassMaterial.INSTANCE) {
+        if (mat == Material.GLASS || mat == AEMaterials.GLASS) {
             if (adjacentBlockState.getRenderType() == state.getRenderType()) {
                 return true;
             }