PWGHF: Add D+ -> KKPi flag for MC (#4616)

* PWGHF: Add nSigma TPC TOF to Ds tree creator output

* MegaLinter fixes

* PWGHF: Add D+ -> KKPi flag

* Please consider the following formatting changes

* Add comments and fixed formatting

* Please consider the following formatting changes

* Refactored candidateCreator D meson selections

* MegaLinter fixes

* Fix formatting

* Imlemented suggestions

---------

Co-authored-by: ALICE Action Bot <alibuild@cern.ch>

Author: fchinu