cleanupnodes: trust caller when "moves" is not None

Authored by martinvonz.

Description

cleanupnodes: trust caller when "moves" is not None

If "moves" (indicating how to move bookmarks) is None, we fill it out
based on "replacements" (indicating which obsmarkers to add). If
"moves" is not None, we would still add items based on
"replacements". This makes it impossible to pass "moves={}" and not
move bookmarks, which surprised me. The only caller that currently
passes a value for "moves" was the rebase extension and there we were
already adding bookmark moves corresponding to obsmarker additions, so
it should not be impacted.

Differential Revision: https://phab.mercurial-scm.org/D5391

Details