Deploy on pypi

The pyicat-plus ships with a versions of the master xml file as a fallback when it cannot access this repo (e.g. no network): https://gitlab.esrf.fr/icat/pyicat-plus/-/tree/main/src/pyicat_plus/metadata

It would be better to make this project pip installable, shipping the xml file.

Use case: pyicat-plus!50 (merged)