dirstatemap: add a common `_insert_entry` method for dirstatemap This method is called to add a new DirstateItem to the map. Each variant have a different implementation (which is … the point). Differential Revision: https://phab.mercurial-scm.org/D11573

dirstatemap: use a common implementation for `dirstatemap.set_untracked` We can now make sure they use the same code, and drop the older, out of sync, implementation of `set_untracked` for the rust wrapper. Differential Revision: https://phab.mercurial-scm.org/D11572

dirstatemap: add a common `_refresh_entry` method for dirstatemap This method is called once a DirstateItem have been modified to apply the change on the dirstatemap if necessary. Each variant have a different implementation (which is … the point). We use `addfile` for the rustmap and not `set_dirstate_item` because we need to keep the internal counter up to date and `set_dirstate_item` does not do it. Differential Revision: https://phab.mercurial-scm.org/D11571

dirstatemap: create `_dirs_incr/_dirs_decr` methods on the common class The Rust wrapper does not need them. However having a default, no-op, implementation will help use to write code used by both implementation. Differential Revision: https://phab.mercurial-scm.org/D11570

dirstatemap: small rework of the `set_untracked` method This shuffle the code a bit to have it flowing more "naturally". This will help us to create a common version of this code in the next changesets. Differential Revision: https://phab.mercurial-scm.org/D11569

dirstatemap: arrange methods by category The dirstatemap code cover various aspects, it grow a bit messy over the years. So we shuffle the code around into some documented categories. This will help use to clean up the code. No code was changed in this changeset, only code move. Differential Revision: https://phab.mercurial-scm.org/D11568

dirstatemap: move a multiple simple functions in the common class These are small and simple, lets factor them out. Differential Revision: https://phab.mercurial-scm.org/D11567

dirstatemap: rename `_rustmap` to `_map` This match the name of the `map` for the other implementation and will make it simpler to share code between the two. Differential Revision: https://phab.mercurial-scm.org/D11566

dirstatemap: use a common __init__ for dirstatemap This is the first and simplest things to put in common. Differential Revision: https://phab.mercurial-scm.org/D11565

dirstatemap: introduce a common base for the dirstatemap class We have two dirstatemaps class. One for the python version of the dirstate map and one for the Rust version (that has a python wrapper to deal with some aspect of it). We end up with duplicated code between them, so we introduce a common base class to start migrating common code in them. Differential Revision: https://phab.mercurial-scm.org/D11564