exchange: drop unused '_getbookmarks' function The function was introduced in 8491845a75b2 in mid-November 2016 but is never used anywhere in core.

bookmark: use bundle2 debug output in one push tests Having more details about the push process will help to track changes made to the actual exchange.

pull: store binary node in pullop.remotebookmarks The internal representation of bookmark value is binary. The fact we stored 'hex' was an implementation detail from using pushkey. We move the values in 'pullop.remotebookmarks' to binary before adding a way to exchange bookmarks not based on pushkey.

config: rename allow_push to allow-push As part of ConfigConsolidationPlan [1], rename the option according to the new UI guidelines [2] and add an alias for backward compatibility. [1]: https://www.mercurial-scm.org/wiki/ConfigConsolidationPlan [2]: https://www.mercurial-scm.org/wiki/UIGuideline#adding_new_options