Improve message accessibility for colorblind users

[rhoerr]

Feedback from Samuele: It's hard for a color-blind person to tell the difference between yellow notice banners and green success banners (and possibly red error messages).

It would help to make the colors more saturated, or maybe add icons by message type.

[GrimLink]

@rhoerr is this issue still relevant, for the colors?

Looking at the message types, there is always a icon to help the status color for users with specific color blindness.

Success	Warning	Error	Info

The one issue I did notice, when testing, is the lack of a border!
The success message disappears into just a icon and text when the user has Achromatopsia.
Also from a prefer contrast mode a border would be better.

Mage-OS	Hyvä Commerce