Bug 21628: (follow-up) Indentation and filter corrections

Bug 21628: (follow-up) Indentation and filter corrections

This patch modifies the new waiting_holds.inc to fix the indentation. A
template variable filter has been added to quiet QA tool warnings.
Buttons are now styled as Bootstrap buttons.

To test, apply the patch and view the holds report. Confirm that
everything looks correct. Validate the HTML and confirm that there are
no errors in the HTML of the body of the page.

Followed test plan, everything looked correct and no HTML errors on
waitingreserves.tt found by HTML validator

Signed-off-by: Alex Buckley <alexbuckley@catalyst.net.nz>
Signed-off-by: Josef Moravec <josef.moravec@gmail.com>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>