context menu deployed on PTM peptide

src/grouping/ptm/ptmgroupingexperiment.h

src/gui/ptm_peptide_list_view/ptmpeptidelistwindow.cpp

src/gui/ptm_peptide_list_view/ptmpeptidelistwindow.h

src/gui/ptm_peptide_list_view/ptmpeptidetablemodel.cpp

src/gui/ptm_peptide_list_view/ptmpeptidetablemodel.h

src/gui/ptm_peptide_list_view/ptmpeptidetableproxymodel.cpp

src/gui/ptm_peptide_list_view/ptmpeptidetableproxymodel.h