store: use the new boolean property in `narrow`

store: use the boolean property in `store`

store: introduce boolean property for revlog type This will avoid exposing implementation details to more generic code.

store: issue a single entry for each revlog We now yield a single entry, with data about each files involved. This help to simplify multiple code using this and it will help to further simplify and fixes the streaming code.

store: rename `unencoded_path` to `entry_path` for StoreEntry This remove the ambiguity with StoreFile and make sure use code will be using the right API.

store: do the revlog matching on entry directly This is the last blocker to safely merge the revlog files in a single entry.

store: split the wrapping of encodedstore between _wrap and datafiles The `datafiles` method of `basicstore` is doing a lot of work that should be done on decoded filename. So we now wrap `_walk` to do the decoding, and less work in `datafiles`. This is necessary to make sure file from the same revlog can be grouped together.

store: introduce a main_file_path method for revlog This help code that need to point revlog to an index file. This is put to use in the upgrade code.

upgrade: actually use StoreEntry API to create revlog Lets make use of the semanctic of the object we are passed.

upgrade: use StoreEntry object in upgrade We will make more use of the API in the next changeset, but just moving to use entry is a significant change for the engine codebase.

upgrade: drop a quick fix that is not longer necessary We won't issue bad revlog from topfile anymore.

store: use StoreEntry API instead of parsing filename in largefile This is more explicit and more robust.

store: use StoreEntry API instead of parsing filename when listing manifestlog This is more explicit and more robust.

store: use StoreEntry API instead of parsing filename when fixing issue6528 This is more explicit and more robust. We also introduce a small output change as it make things simpler and this is a affecting a debug-command.

store: use StoreEntry API instead of parsing filename in remotefilelog This is more explicit and more robust.

store: use StoreEntry API instead of parsing filename in narrow This is more explicit and more robust.

store: add a `target_id` attribute on RevlogStoreEntry This hold the "target" (file, directory, etc) of a revlog. Having this available will help a lot of code to avoid direct file path access.

store: actually tag tree manifest revlogs as manifest revlogs It turn out we have been mislabeling these for a long while. This is now fixed.

store: also gather files per revlog in `topfiles` This conclude out revlog gathering.

store: also group files by revlog in fncache version of datafiles One more step.

store: add logic to group revlog file together For now each file get its own entry, this will help stopping this, soon™. We use such gathering in the `basicstore` code.

store: change `_walk` return to `(filename, (type, size))` If we are to group file per revlog, having the filename as the "main key" will be useful. This change will make the following changes clearer.

store: lazily get file size on demand for the fncache case We don't have the information in the first place, so we can avoid querying the file system inconditionnaly for use case we don't needs it. This change requires the StoreFile class to be passed a vfs to retrieve the file_size if needed. In the non-fncache case, we already have the information from file system walking, so we keep it and use it.

store: only access is_volatile information through the file object This make sure other code only access this information through the proper API, and it prepare for store entries to be able to agregate multiple files.