Migrate to a new optimade widget

> Hopefully the psdi issue is fixed now and the (legacy) aiidalab widget works. But yes, it currently uses the old and unstable widget. @Bud-Macaulay also built a new client (and a widget prototype) here: https://github.com/materialscloud-org/tools-optimadeclient-react, which would be nice if aiidalab could switch to. But at the moment maybe the widget needs a bit of documentation/examples, to make the transition easier.

_Originally posted by @eimrek in [#731](https://github.com/aiidalab/aiidalab-widgets-base/issues/731#issuecomment-3990254431)_