Bug 1883987: Help Icon for Authentication plugin not aligned properly

- add new option to pieform element help: top
- add help to rendered div in new order if value is top

Change-Id: I0773d94e8131a6616c3033e7207c7c8f2d4319c8
Signed-off-by: Lisa Seeto <lisaseeto@catalyst.net.nz>
(cherry picked from commit 4f85aeca)
(cherry picked from commit 5a2b6fbb)