pull: move bookmark pulling into its own function This requires adding an attribute on the pulloperation object. The bookmark pulling is protected behind a "todostep" as other steps of pull.

pull: perform the todostep inside functions handling old way of pulling This matches what is done during push.

bookmark: remove now unused `pushtoremote` function Everything is unified in the push discovery now.

push: gather all bookmark decisions together The discovery phases for bookmarks now use the list of explicitly pushed bookmarks to do addition, removal and overwriting. Tests are impacted because this reduces the amount of listkeys calls issued, removes some duplicated messages and improves the accuracy of some messages.

push: prepare the issue of multiple kinds of messages To gather all the bookmark pushing actions together, we need code performing those actions to be ready for them. We need to be able to produce different messages for different actions.

push: set bkresult when pushing bookmarks through bundle2

clone: remove duplicated bookmark pulling Now that all clone methods (copy, pull and push) also transport bookmarks, we can safely drop the manual pulling that was performed during clone.