Merge branch "spectroscopi-ellipsometry-consolidation" into "main"

spectroscopi-ellipsometry-consolidation: Quoted strings get flattened in YAML. Block ones (indicated by the '|' at the beginning of the string) are taken with all white spaces as well, as long as the string is indented properly. The original indentation is taken off.

Corrected and updated version of NXellipsometry.yaml and associated nxdl file.