evolve: advertise obsmarker creation in the transation hook This will let extensions hooks on marker exchange.

evolve: add bytes and new marker data when processing part This will helps use to keep printing useful message when pulling through bundle2.

evolve: add a push pass using bundle2 Instead of using a dedicated wireprotocol commands, we use bundle2 to transmit an obs marker parts. This aims at both testing bundle2 more and to limit the amount of special code we needs to put in simple for server to fit our needs. The massive test changes comes from the fact we can use this fast path for both remote and local push.

evolve: make exchange output compact in the old pushkey case too.

evolve: compatibility with memfilectx change The future 3.1 have have more sophisticated memfilectx object. We add a compatibility layer for them.

evolve: abstract access to context.memfilectx This class is getting altered in the future Mercurial 3.1.0. This changeset prepare a compatibility layer.

import: drop version check for ``import --obsolete`` This code base does not support anything below mercurial-3.0 anyway.

evolve: bump requirement to 3.0.1 Use of bundle2 for pulling will require this version or above.

test: fix test-import condition The help text is ``"only(`` not `` only(``

merge with stable