Use check_markup() on fundraiser's confirmation_page_body using confirmation_page_format as the selected filter format

Use check_markup() on fundraiser's confirmation_page_body using confirmation_page_format as the selected filter format.

While there is a format selector on the admin form for confirmation messages, it was not being utilized by the theme preprocess function. This had security implications as well as rendering certain input filters like PHP ineffective.

The confirmation message is now run through check_markup() before any token replacements or theme output occurs.