♻️(frontend) adapt custom blocks to new implementation

Last release of Blocknote introduced breaking
changes for custom blocks.
We adapted our custom blocks to the new
implementation.
"code-block" is considered as a block now, we
update the way to import and use it.
The custom blocks should be now more tiptap friendly.

src/frontend/package.json

@@ -36,6 +36,7 @@
     "@types/react-dom": "19.2.0",
     "@typescript-eslint/eslint-plugin": "8.45.0",
     "@typescript-eslint/parser": "8.45.0",
+    "docx": "9.5.0",
     "eslint": "9.37.0",
     "react": "19.2.0",
     "react-dom": "19.2.0",