localrepo/branchcache: remove lbranchmap(), convert users to use utf-8 names
We don't need a "local-charset" aware branchmap() function, we can convert the
names when needed during the output.
localrepo/branchcache: kill unused localrepo.branchcache
The UTF-8 version of the branchcache is the master, always up-to-date, we can
rename it to localrepo._branchcache.
localrepo/branchcache: rebuild the "charset-aware" branchcache when needed
It's simpler and the two cache weren't always in sync otherwise:
localrepo.branchcache would not be updated after calling branchmap()
churn: fix --progress (broken by
f3d60543924f)