Adding lmvm combinatorial pairs procedure

Develop combinatorial BG procedure and add corresponding histograms

Correct pairing in CB and reverse formatting of python macros

Add Single Particle Yield Histos

Particle Yield and Acceptance of Electrons and Positrons is observed for various detector combinations.
Formatting of python scripts after they had been tored by wrong application of clang format.

WIP Add single particle histos

WIP: Update single particle histograms

WIP: Add histograms for nPoint

Number of points the electrons / positrons leave in the various detectors

Modify macros for common production

Also some small adaptions in CbmAnaDielectronTask.cxx and in ana and litqa macros were done.

Apply clang format