delensalot.run and simlib tweaks

[Sebastian-Belkner]

A few improvements I ran into when migrating back to CSCS.

• delensalot jobs are now listed hierarchically. If MAP_lensrec requested, run will build a job list of genrate_sim, QE_lensrec, MAP_lensrec and executes them in the right order. This allowed to remove dependencies within the jobmodels
• two purger functions for convenience, to remove TEMP data with delensalot
• simlib now stores data in dirnames which are easier human-readable
• MPI setup now checks for pmi, mpi, and program which called the process
• Fix to dtype for generating noise