Responsive: Allow '0' to hide elements

[melloware]

Description
Sometimes, I'd like a component (or simply a div) to be shown only on desktop. I'd like it to disappear (at least visually) on mobile, and vice-versa.

Originally reported in Primefaces: primefaces/primefaces#6098

Consider this social login example, I'd like to show:

• "Or sign in manually:" on mobile only (e.g., through a hypothetical <div class="ui-g-12 ui-md-0 ui-lg-0"/>
• "Or:" on desktop only (e.g., through a hypothetical <div class="ui-g-0 ui-md-2 ui-lg-2"/>

[cagataycivici]

We have display utilities for this so I rather not duplicate the functionality, please review;

https://primefaces.org/primeng/showcase/#/primeflex/display