feat: enable basename for multi cluster version

Author: artemmufazalov

package.json

@@ -68,6 +68,7 @@
     "build": "rm -rf build && DISABLE_ESLINT_PLUGIN=true CI=true react-app-rewired build",
     "//build:embedded": "echo 'PUBLIC_URL is a setting for create-react-app. Embedded version is built and hosted as is on ydb servers, with no way of knowing the final URL pattern. PUBLIC_URL=. keeps paths to all static relative, allowing servers to handle them as needed'",
     "build:embedded": "GENERATE_SOURCEMAP=false PUBLIC_URL=. REACT_APP_BACKEND=http://localhost:8765 REACT_APP_META_BACKEND=undefined npm run build",
+    "build:embedded:mc": "GENERATE_SOURCEMAP=false PUBLIC_URL=. REACT_APP_BACKEND= REACT_APP_META_BACKEND= npm run build",
     "build:embedded:archive": "npm run build:embedded && mv build embedded-ui && zip -r embedded-ui.zip embedded-ui && rm -rf embedded-ui",
     "lint": "run-p lint:*",
     "lint:js": "eslint  --ext .js,.jsx,.ts,.tsx .",