B2XMuMuLine from 2018-patches

Copied Phys/StrippingSelections/python/StrippingSelections/StrippingRD/StrippingB2XMuMu.py from 2018-patches

Copied Phys/IsolationTools/src/RelInfoBKstarMuMuHad.* from 2018-patches

This only compiles with Phys/DaVinciTypes/Kernel/RelatedInfoNamed.h from 2018-patches of the Phys package, the MR to port this change also to 2017-patches of the Phys package is linked here.

The test on 30k data events shows the following timings:

StrippingReport                                                INFO Event 30000, Good event 30000
 |                                              *Decision name*|*Rate,%*|*Accepted*| *Mult*|*ms/evt*|
 |_StrippingGlobal_                                            |  0.4600|	138|	   |  12.470|
 |_StrippingSequenceStreamLeptonic_                            |  0.4600|	138|	   |  12.134|
 |!StrippingB2XMuMu_Line                                       |  0.4600|	138|  5.551|  10.451|
 |!StrippingB2XMuMu_Line_TIMING                                |  0.4600|	138|  5.551|   0.175|

FILES TO MERGE: StrippingB2XMuMu.py