ui: replace stupid react-split-pane with allotment

packages/ui-default/package.json

@@ -40,6 +40,7 @@
     "@types/sharedworker": "^0.0.91",
     "@types/webpack-env": "^1.18.0",
     "@vscode/codicons": "^0.0.32",
+    "allotment": "^1.18.1",
     "autoprefixer": "^10.4.13",
     "browser-update": "^3.3.44",
     "chalk": "^5.2.0",
@@ -87,7 +88,6 @@
     "react-dom": "^18.2.0",
     "react-query": "^3.39.3",
     "react-redux": "^8.0.5",
-    "react-split-pane": "^0.1.92",
     "reconnecting-websocket": "^4.4.0",
     "redux": "^4.2.1",
     "redux-logger": "^3.0.6",