fix: Fix textures always being stitched

Textures were always being stitched instead of loaded from cache, because `AtlasTextureIdentifier` did not override `equals()` and `hashCode()`.

common/src/main/java/io/github/steveplays28/blinkload/util/resource/json/AtlasTextureIdentifier.java

@@ -3,6 +3,8 @@
 import net.minecraft.util.Identifier;
 import org.jetbrains.annotations.Nullable;
 
+import java.util.Objects;
+
 @SuppressWarnings({"FieldCanBeLocal", "FieldMayBeFinal", "unused"})
 public class AtlasTextureIdentifier {
 	private @Nullable Identifier identifier;
@@ -20,4 +22,29 @@ public AtlasTextureIdentifier(@Nullable Identifier identifier, @Nullable Integer
 	public @Nullable Integer getMipLevel() {
 		return mipLevel;
 	}
+
+	@Override
+	public boolean equals(Object other) {
+		if (!(other instanceof AtlasTextureIdentifier otherAtlasTextureIdentifier)) {
+			return false;
+		}
+
+		return Objects.equals(getIdentifier(), otherAtlasTextureIdentifier.getIdentifier()) && Objects.equals(
+				getMipLevel(), otherAtlasTextureIdentifier.getMipLevel());
+	}
+
+	@Override
+	public int hashCode() {
+		var identifierHashCode = 1;
+		if (getIdentifier() != null) {
+			identifierHashCode = getIdentifier().hashCode();
+		}
+
+		var mipLevelHashCode = 1;
+		if (getMipLevel() != null) {
+			mipLevelHashCode = getMipLevel().hashCode();
+		}
+
+		return identifierHashCode * mipLevelHashCode;
+	}
 }