dRICH: vessel materials and thicknesses

**Is your feature request related to a problem? Please describe.**
See slides from Alessandro: https://indico.bnl.gov/event/19746/

**Describe the solution you'd like**
The vessel is currently thin Aluminum; consider updating it to be more realistic, following Alessandro's slides.

Start by reviewing Alessandro's slides and locating the current dRICH vessel geometry and its thin Aluminum material definition. Update the vessel materials and thicknesses to match the more realistic design described in the slides, then verify that the resulting geometry reflects those changes.

Written by the indexing model from the issue text.