rotate cryostat steel structure in protodune-vd driftx geometry

[thkosc]

Following header comment of file generate_protodunevd_v4_refactored.pl, I rotated the steel structure of the cryostat. As for now, protodune-vd with drift along x used a non-rotated cryostat (same as protodune-hd) with walls pushed a little bit to avoid overlaps with inside components (because protodune is less high than large).
The latter had become incompatible with the CRT pannels included later (v3), as CRTs were located inside the cryostat.
I also added header comment to explain the few changes.

I'm attaching with the pull request a script file to draw the gdml geometry files. It can be compiled and executed in a root session, with the file name as argument (I think package root-geom must be installed). Ht escript has extension 'txt' because github won't accept the '.C' extension, so you just need to change the extension manually.

This geometry now has 3 overlaps which are all beam related. I'm getting in touch with the beam experts to solve this.

drawProtoDune.txt

[tomjunk]

I was able to reproduce the overlap check:

root [1] gGeoManager->Import("protodunevd_v4_refactored_nowires.gdml");
root [2] gGeoManager->CheckOverlaps(0.1);
Info in TGeoNodeMatrix::CheckOverlaps: Checking overlaps for volWorld and daughters within 0.1
Check overlaps: [==========] 2625 [100.00 %] 00:00
Info in TGeoNodeMatrix::CheckOverlaps: Number of illegal overlaps/extrusions : 3

root [3] gGeoManager->PrintOverlaps();
=== Overlaps for Default ===
= Overlap ov00000: volCryostat extruded by: volCryostat/volBeamPlIIUSCap_0 ovlp=19.5539
= Overlap ov00001: volCryostat extruded by: volCryostat/volBeamPlIIMod_0 ovlp=19.202
= Overlap ov00002: volDetEnclosure/volSteelSupport_RS overlapping volDetEnclosure/volBeamPipe_0 ovlp=7.37784

converting this PR to a draft so we don't accidentally merge it.