Add text-transform CSS

From: Laurence Zaysser, Digital project managerSEJER

In the OPS, section "3.0: OPS Style Sheets", there is a very useful property missing on text properties’ selection. It is text-transform : uppercase.

This property is absolutely necessary to manage case through style sheet, instead of character encoding.

It is the natural complement to small caps (which is already in the standard, but not supported by ADE). Cf. font variant:small-caps