Merge branch 'en/merge-tests'

Preparation for a new merge strategy. * en/merge-tests: t6423: add more details about direct resolution of directories t6423: note improved ort handling with untracked files t6423, t6436: note improved ort handling with dirty files merge tests: expect slight differences in output for recursive vs. ort t6423: expect improved conflict markers labels in the ort backend t6404, t6423: expect improved rename/delete handling in ort backend t6416: correct expectation for rename/rename(1to2) + directory/file merge tests: expect improved directory/file conflict handling in ort t/: new helper for tests that pass with ort but fail with recursive