support multiple scenes and passing between them

src/api/mod.rs

@@ -48,7 +48,10 @@ pub enum Request {
         amount: usize,
     },
     // Map requests
-    GetCurrentScene,
+    GetScene {
+        id: usize,
+    },
+    GetSceneList,
     GetTokens {
         scene: usize,
     },
@@ -82,6 +85,9 @@ pub enum Response {
         grid_cell_size: Option<f32>,
         grid_offset: Option<[f32; 2]>,
     },
+    SceneList {
+        scenes: Vec<(usize, String)>,
+    },
     MoveToken {
         token_id: usize,
         x: f32,