fdo#75256 Improve Sifr Icon Theme

Update the buggy insertformular icon and new annotation icons for sifr.

Change-Id: I1ff6ea4ed7c4de474fd1ecfbc4cc76eac6ba1287
Reviewed-on: https://gerrit.libreoffice.org/12231
Reviewed-by: Samuel Mehrbrodt <s.mehrbrodt@gmail.com>
Tested-by: Samuel Mehrbrodt <s.mehrbrodt@gmail.com>