refactor: some restructuring

- move structs inside `sr_tools.rs` into individual file
- implement in-game equip handler (relic & lightcone)

common/src/structs/scene.rs

@@ -0,0 +1,56 @@
+use proto::{MotionInfo, Vector};
+use serde::{Deserialize, Serialize};
+
+use crate::impl_from;
+
+// SCENE
+#[derive(Serialize, Deserialize, Debug, Clone)]
+pub struct Scene {
+    pub plane_id: u32,
+    pub floor_id: u32,
+    pub entry_id: u32,
+}
+
+impl Default for Scene {
+    fn default() -> Self {
+        Self {
+            plane_id: 20411,
+            floor_id: 20411001,
+            entry_id: 2041101,
+        }
+    }
+}
+
+#[derive(Debug, Serialize, Deserialize, Clone)]
+pub struct Position {
+    pub x: i32,
+    pub y: i32,
+    pub z: i32,
+    pub rot_y: i32,
+}
+
+impl Default for Position {
+    fn default() -> Self {
+        Position {
+            x: -26968,
+            y: 78953,
+            z: 14457,
+            rot_y: 11858,
+        }
+    }
+}
+
+impl_from!(Position, MotionInfo, |value| {
+    MotionInfo {
+        rot: Some(Vector {
+            x: 0,
+            y: value.rot_y,
+            z: 0,
+        }),
+        pos: Some(Vector {
+            x: value.x,
+            y: value.y,
+            z: value.z,
+        }),
+    }
+});