GeoModelXml improvements: remove the automatic insertion of NameTags and Identifiers, expand Examples.

This MR removes the automatic insertion of NameTag and Identifier GeoModel nodes when processing <logvol> XML entities in GeoModelXml.

Now, NameTags and Identifiers are inserted only when requested; i.e., when the relevant, optional flags are specified in the corresponding XML entity.

It also fixes a crash on hardcoded position of PV, by commenting call to the not-used addAlignable function (at the moment, it only prints log msgs).