changegroup: consolidate tree manifests sending into cg1packer Previously, we overrode a method to control how manifests were serialized. This method was redefined on cg3packer to send tree manifests. This commit moves the tree manifests sending variation to cg1packer and teaches the cgpacker constructor to control which version to use. After these changes, cg3packer was empty. So it has been removed. Differential Revision: https://phab.mercurial-scm.org/D4081