Bundle CSS in order to support more bundlers

[silvester-pari]

Currently, CSS from pacakges such as ol are imported with the ?inline mode - see e.g.

EOxElements/elements/map/src/main.js

Line 4 in 333e324

import olCss from "ol/ol.css?inline";

This works for Vite and bundlers that support this feature, but other bundlers won't be able to use this, and still need to use the bundled version of the elements.
Seeing that we have a similar issue somewhat solved in https://github.com/EOX-A/EOxElements/blob/333e324def0354992fadd4640fc2ee9b72a545b4/tasks/init-style.js we caan probably find an unified solution for handling all CSS in the repo.