Merge branch 'en/batch-prefetch'

In a lazy clone, "git cherry" and "git grep" often fetch necessary blob objects one by one from promisor remotes. It has been corrected to collect necessary object names and fetch them in bulk to gain reasonable performance. * en/batch-prefetch: grep: prefetch necessary blobs builtin/log: prefetch necessary blobs for `git cherry` patch-ids.h: add missing trailing parenthesis in documentation comment promisor-remote: document caller filtering contract