OstapHEP/ostap: v1.9.7.4

v1.9.7.4 New features: add new test/example test_fitting_simfit7 to compre simultenoud fit versus fit with constraints fit1d : add suffin to the name for automatically created backgronus component add Ostap::Math::hotelling function to estgimate Hotelling t2-statistics make use of Ostap::Math::hotelling function in reweighting tests add new argument respect_groups for split_string function insert rootException for several stat-related functions improve printout for Ostap::Functions::Expression and friends add posssibility to enable global thread safety and implicit MC via .ostaprc configuirtaion file update/modify/fix Ostap::Math::Moment_ and Ostap::Math::WMoment_ add Ostap::StatVar::the_moment add the_moment method for TTree, RooAbsData and DataFrame Backward incompatible: Bug fixes