scm: mercurial: add test helper method to switch short or long id (#14361)

git-svn-id: http://svn.redmine.org/redmine/trunk@12771 e93f8b46-1217-0410-a6f0-8f06a7374b81
scm: mercurial: use scmid_for_assert in assert_copied_files (#14361)

git-svn-id: http://svn.redmine.org/redmine/trunk@12772 e93f8b46-1217-0410-a6f0-8f06a7374b81
scm: mercurial: use scmid_for_assert in assert_entry (#14361)

git-svn-id: http://svn.redmine.org/redmine/trunk@12773 e93f8b46-1217-0410-a6f0-8f06a7374b81