fdo#75256 Improve Sifr Icon Theme

* Correct the alignment of some icons.
* New icons for quit, save as, close and avmediaplayer

Change-Id: I7ef40c410682e5c6854e0c3a12abf186378bdfb5
Reviewed-on: https://gerrit.libreoffice.org/11345
Reviewed-by: Samuel Mehrbrodt <s.mehrbrodt@gmail.com>
Tested-by: Samuel Mehrbrodt <s.mehrbrodt@gmail.com>