ParseCssBlockProperties does not parse url attribute correctly

Due to failing to account for the existence of quoted strings for URL, fails to parse DATA urls due to the existence of a ';' in the string

eg
url('data:image/gif;base64,R0lGOD'); produces url('data:image/gif;

Implementation needs to allow for this in URL and for Font-Family at least

Start by locating ParseCssBlockProperties and trace how it splits URL and Font-Family values. Reproduce the data URL example with a semicolon inside the quoted string; done means the complete quoted URL remains intact instead of being truncated.

Written by the indexing model from the issue text.