allow web spreadsheet key scrolling to add rows and columns (#3706)


git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@34491 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
improve web spreadsheet cell editor styling (#3706)


git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@34492 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e