Merge branch 'en/ort-conflict-handling' into en/merge-ort-perf

* en/ort-conflict-handling: merge-ort: add handling for different types of files at same path merge-ort: copy find_first_merges() implementation from merge-recursive.c merge-ort: implement format_commit() merge-ort: copy and adapt merge_submodule() from merge-recursive.c merge-ort: copy and adapt merge_3way() from merge-recursive.c merge-ort: flesh out implementation of handle_content_merge() merge-ort: handle book-keeping around two- and three-way content merge merge-ort: implement unique_path() helper merge-ort: handle directory/file conflicts that remain merge-ort: handle D/F conflict where directory disappears due to merge