feat: Unfinished level loading

- Added level struct
- Added loading tests
- Partially implemented level setting up system

src/tests/level.rs

@@ -0,0 +1,16 @@
+use super::super::*;
+
+#[test]
+fn deserialize_levels() {
+    let level_str = include_str!("../../assets/levels/level.toml");
+    let level_alt_str = include_str!("../../assets/levels/level_alt.toml");
+    let level = toml::de::from_str::<layout::asset::structs::LevelAsset>(level_str).unwrap();
+    let level_alt = toml::de::from_str::<layout::asset::structs::LevelAsset>(level_alt_str).unwrap();
+
+    assert_eq!(level.meta, level_alt.meta);
+    assert_eq!(level.interactive, level_alt.interactive);
+    for (tiles_id, tiles) in level.tiles.tiles {
+        let (_, other_tiles) = level_alt.tiles.iter().find(|(k, _)| k == &&tiles_id).unwrap();
+        assert_eq!(&tiles, other_tiles);
+    }
+}