fdo#80654 - Add icon to 'Close Preview' button in Page Preview toolbar

Change-Id: I287f8549b6bfb8435c6ad1daabbb8ac2c1a51c2b
Reviewed-on: https://gerrit.libreoffice.org/11576
Reviewed-by: Samuel Mehrbrodt <s.mehrbrodt@gmail.com>
Tested-by: Samuel Mehrbrodt <s.mehrbrodt@gmail.com>
Disable HTML any check which uses twip->pixel conversion on OSX

Change-Id: Ifae32518aa503bfa8c912c18220bbbf28b76be09