Propagate number of processors from Transformations or Productions down to Jobs description

[fstagni]

Nowhere in the TransformationSystem it is called Job().setNumberOfProcessors(). This is "correct", because the logic can be added to the ProductionSystem ("can an application/step run multicore?" and "what are its limits?").
Still, this is quite VO-dependant, but if any it should be added to Vanilla DIRAC ProductionSystem.

All considerations above are also valid for setting RAM limits, which is introduced in #8232

[chaen]

I think it is a more general problem of propagating things from the TS down to tasks, down to Requests/Jobs.

We have a similar issue with:

• sourceSE that Xiaomei reported
• Activities for FTS
• Sandbox (@chrisburr )

[fstagni]

Also "Tag": #7862