tests: add a test showing bookmark not moving in-case of `hg fold`
This patch adds a test showing that bookmark is not moved when doing `hg fold`.
This test represents issue 5772.
# utility to setup pythonpath to point into the tested repository
export SRCDIR=`dirname $TESTDIR`
if [ -n "$PYTHONPATH" ]; then
export HGTEST_ORIG_PYTHONPATH=$PYTHONPATH
export PYTHONPATH=$SRCDIR:$PYTHONPATH
else
export PYTHONPATH=$SRCDIR
fi