CollaboraOnline#6546 enable automatic color in default paragraph style

[timar]

use the xml token "use-window-font-color" to toggle auto color on.

https://github.com/CollaboraOnline/online/issues/6546

[phil-davis]

@pako81 who can review this sort of thing?

[pako81]

@mrow4a can you please review this?

[mrow4a]

lets merge after release-4.0.0 is done in https://github.com/owncloud/richdocuments/issues/501