Merge branch 'ps/history' into pw/replay-drop-empty

* ps/history:
  builtin/history: implement "split" subcommand
  cache-tree: allow writing in-memory index as tree
  add-patch: allow disabling editing of hunks
  add-patch: add support for in-memory index patching
  add-patch: remove dependency on "add-interactive" subsystem
  add-patch: split out `struct interactive_options`
  add-patch: split out header from "add-interactive.h"
  builtin/history: implement "reword" subcommand
  builtin: add new "history" command
  replay: stop using `the_repository`
  replay: extract logic to pick commits
  wt-status: provide function to expose status for trees
  replay: do not copy "gpgsign-sha256" header