scmutil: make shortesthexnodeidprefix() use unfiltered repo
Both callers were doing this, and resolvehexnodeidprefix() was also
working on the unfiltered repo, so it makes more sense to have it all
in one place.
Differential Revision: https://phab.mercurial-scm.org/D3313
== Local
Ready.
Un and Deux
Eins und Zwei
One and Two
Eins und Zwei
Uno und Due
== Remote
Ready.
REQ: foo?one=Vo&two=Efvy
-> Vo!boe!Efvy
Un and Deux
REQ: bar?b=Fjot&a=[xfj
-> Fjot!voe![xfj
Eins und Zwei
REQ: batch?cmds=foo:one=Pof,two=Uxp;bar:b=Fjot,a=[xfj;bar:b=Vop,a=Evf
-> Pof!boe!Uxp;Fjot!voe![xfj;Vop!voe!Evf
One and Two
Eins und Zwei
Uno und Due