bundle: avoid repo.lookup() for converting revnum to nodeid Differential Revision: https://phab.mercurial-scm.org/D3048

push: avoid using repo.lookup() for converting to nodeid repo.lookup(x) currently simply does repo[x].node(), which supports various types of inputs. As I explained in 0194dac77c93 (scmutil: add method for looking up a context given a revision symbol, 2018-04-02), I'd like to split that up so we use the new scmutil.revsymbol() for string inputs repo[x] for integer revnums and binary nodeids. Since repo.lookup() seems to exist in order to serve peer.lookup(), I think it should be calling revsymbol. However, we have several callers that use repo.lookup() with something that's not a string, so we need to remove those first. This patch starts doing that. Many more will follow. Differential Revision: https://phab.mercurial-scm.org/D3047