Cleaned up Tango SVG icons

Some of the icons embedded multiple fonts in base64 encoded form.

Commands run:
find . -name '*.svg' -exec sed -i '/<style.*/,/<\/style>/d' {} + \;
find . -name '*.svg' -exec sh -c 'svgcleaner "$1" "$1"' x {} \;

Svgcleaner being https://github.com/RazrFalcon/svgcleaner

Change-Id: Iffff65438a6ed34ed956aeff041c6f8925cffdaa
Reviewed-on: https://gerrit.libreoffice.org/69385
Tested-by: Jenkins
Reviewed-by: Adolfo Jayme Barrientos <fitojb@ubuntu.com>