Extend level crossing in IS by barriers and lights

Background

currently levelCrossingIS/protection has no children. This is not enough to model complex level crossings.

Links

• Forum discussion:
  • Georg Boasson, 02.06.2022: https://www.railml.org/forum/index.php?t=msg&th=880&start=0&
  • Larissa Zhuchyi, 23.01.2024: https://www.railml.org/forum/index.php?t=msg&th=939&start=0&

Proposed solution railML 3.3

levelCrossingIS/protection should have additional <barriers> and <lights> children.

both <barriers> and <lights> should have

• name and spot, linear, areaLocation children.
• @roadSide attribute. Possible values are "left" and "right".

After internal discussion it was decided to change naming to <roadSideBarriers> and <roadSideLights>.