DeFT fix to IDs and make M5 optional
This MR fixes a few problems with DeFT, that we worked on with @clemenci
- trivial problems with variables not found in the XML
- problem with the numbering of the Modules that cause assertion errors when testing DeFT
- module M5 has to be optional as it's only visible in station T3
@lohenry could you have a look and/or forward to people who can review this ?