mergeresult: rename _actions to _filemapping This is done because we will be introducing another dict which introduces the same information but with action name as key. Differential Revision: https://phab.mercurial-scm.org/D8829

sparse: pass mergeresult obj in sparse.filterupdatesactions() (API) Not able to see much which can be improved in this function by passing in mergeresult object but for API consistency and no function directly touching actions dict, it sounds like a good idea. Differential Revision: https://phab.mercurial-scm.org/D8828

merge: filter actions before calling _resolvetrivial() In d49e490a9e85252886fd43258803bcad4fc88edb I made _resolvetrivial() to be called after upadting the sparse checkout. Looking at the code now, it seems to that me there is no need to even run _resolvetrivial() on actions which are filtered away. So let's update the actions before passing them into _resolvetrivial(). Differential Revision: https://phab.mercurial-scm.org/D8827

merge: introduce mergeresult.updateactions() and use it We don't want direct editing and access of mergeresult._actions because soon we will like to maintain data in other structures also. Differential Revision: https://phab.mercurial-scm.org/D8826

merge: pass mergeresult instead of actions in _checkunknownfiles() (API) Differential Revision: https://phab.mercurial-scm.org/D8825

merge: pass mergeresult obj instead of actions dict in _resolvetrivial() Differential Revision: https://phab.mercurial-scm.org/D8824

merge: pass mergeresult obj instead of actions in _filternarrowactions() We want to use rich mergeresult object and it's APIs instead of handling a dictionary. Differential Revision: https://phab.mercurial-scm.org/D8823