persistent-nodemap: highlight that node is not sent when streaming

We have a local work-around, however having that data sent in the first place
would be better. So we start with a test that monitor what is sent, and notice
they are not.

Differential Revision: https://phab.mercurial-scm.org/D9736

tests/test-persistent-nodemap.t

@@ -625,7 +625,11 stream clone
 
 The persistent nodemap should exist after a streaming clone
 
-  $ hg clone -U --stream --config ui.ssh="\"$PYTHON\" \"$TESTDIR/dummyssh\"" ssh://user@dummy/test-repo stream-clone --quiet
+  $ hg clone -U --stream --config ui.ssh="\"$PYTHON\" \"$TESTDIR/dummyssh\"" ssh://user@dummy/test-repo stream-clone --debug | egrep '00(changelog|manifest)'
+  adding [s] 00manifest.i (313 KB)
+  adding [s] 00manifest.d (452 KB)
+  adding [s] 00changelog.i (313 KB)
+  adding [s] 00changelog.d (360 KB)
   $ ls -1 stream-clone/.hg/store/ | egrep '00(changelog|manifest)(\.n|-.*\.nd)'
   00changelog-*.nd (glob)
   00changelog.n