Disabled text colour option in the ribbon bar

[wxBen]

This patch allows a disabled text colour to be set in the ribbon bar. I thought I had submitted this patch already, but I see it as a difference between my code and the latest svn, so here it is again.

Existing ribbon bar applications are not impacted, as the disabled colour is by default the same as the enabled colour. But if you set it, then it will be used for disabled text items, as can be seen in the ribbon demo sample case.

[vadz]

Could you please update interface/wx/ribbon/art.h? TIA!

[wxBen]

DisabledColour.diff

[wxBen]

My apologies Vadim, I am getting old! New patch with interface addition attached.

[VZ]

(In [72619]) Add a setting for the disabled text colour to wxRibbon art.

Allow specifying the text for the labels of the disabled items separately.

Closes #14721.