[web] CAS- and Spreadsheetview stylebar changes

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@35535 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
[web] simplified style bar visibility code

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@35536 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e