feat(ui): revised rasterization caching

- use `stable-hash` to generate stable, non-crypto hashes for cache entries, instead of using deep object comparisons
- use an object to store image name caches

invokeai/frontend/web/package.json

@@ -103,6 +103,7 @@
     "roarr": "^7.21.1",
     "serialize-error": "^11.0.3",
     "socket.io-client": "^4.7.5",
+    "stable-hash": "^0.0.4",
     "use-debounce": "^10.0.2",
     "use-device-pixel-ratio": "^1.1.2",
     "uuid": "^10.0.0",