clfilter: ensure changeset creation in the repo is run unfiltered This applies to both creation of new commits and application of changegroups.

clfilter: ensure changegroup generation is run unfiltered Changegroup generation logic needs to be aware of the whole repository to work properly.

clfilter: ensure `rollback` is run unfiltered Rollback logic needs to be aware of the whole repository to work properly.

clfilter: ensure cache invalidation is done on the main unfiltered repo The proxy version will not hold any cache for now. But we have to ensure all cache operations are done on the unfiltered version.

clfilter: ensure that tag logic runs unfiltered The current tag logic is not aware of filtering. We keep the status quo, ensuring that the tag cache is computed as before: without any filtering.

clfilter: ensure `branchcache` logic runs unfiltered The current branchcache construction is not aware of filtering. We keep the status quo, ensuring that the branch cache logic is computed as before: without any filtering.

clfilter: introduce an `unfilteredmethod` decorator This decorator ensure the method in run on an unfiltered version of the repository. See follow-up commit for details. This decorator is not named `unfiltered` because it would clash with the `unfilteredmethod` on `localrepo` itself.

clfilter: introduce an "unfiltered" method on localrepo This commit is part of the changelog level filtering effort. It returns the main "unfiltered" version of a repo-like object. For localrepo this means the same localrepo object. But this method will be overwritten by the filtered versions of a repository to return the core unfiltered version of the repo. Introducing this simple method first allows later commits to prepare for the use of a filtered version of a repository. A new repo method is added because a lot of users may call it. At the end of this series of commits, about 40 calls exist in core and hgext.