rust: Align DirstateEntry internals with Python/C DirstateItem This propagate to this Rust struct the similar change that was made recently to the Python classe and C struct. Namely, instead of storing a four-valued `state` field we now store seven (bit-packed) booleans that give lower-level information. Additionally, the marker values -1 and -2 for mtime and size should not be used internally anymore. They are replaced by some combinations of booleans For now, all uses of of `DirstateEntry` still use the compatibility APIs with `state` and marker values. Later the Rust API for DirstateMap will be increasingly updated to the new style. Also change the expected result of the test_non_normal_other_parent_entries unit test. Only a `DirstateEntry` with `size == -2 && mtime != -1` is affected, but this case never occurs outside of unit tests. `size == -2` was the marker value for "from other parent" entries, where no meaningful mtime is stored. Differential Revision: https://phab.mercurial-scm.org/D11484