Add production bathymetric sonar slice

game/domain/sonar/sonar_material.gd

@@ -0,0 +1,12 @@
+class_name SonarMaterial
+extends RefCounted
+
+enum Value {
+	UNKNOWN,
+	ROCK,
+	METAL,
+}
+
+
+static func is_valid(value: int) -> bool:
+	return value >= Value.UNKNOWN and value <= Value.METAL