manifests: push down expected node length into the parser This strictly enforces the node length in the manifest lines according to what the repository expects. One test case moves large hash testing into the non-treemanifest part as treemanifests don't provide an interface for overriding just the node length for now. Differential Revision: https://phab.mercurial-scm.org/D10533

== 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