PN-7736 Synchronize skin detection between JSP and JS

Checking classes at the body level:
- if only one of these 2 classes are on the body (wf2-skin-nx and wf2-skin-nxt), it means it's intentional or set by the JSP page tag: load the corresponding skin.
- if none of these 2 classes are present or both are present, then use the touch detection mechanism to load the right skin. (in that case, we know that the class was NOT set by the JSP tag).
Well.. I'm assuming your concern is nxs? JSP tag will not deal with it before 2.6.0 at the earliest right? So I'm quite inclined to have that fix quickly out without adding complexity for something that 2.3.0/2.4.0/2.5.0 will not even support.
/wf2-skin-([a-z]+)?/g will not differentiate between having one and only one of our classes versus some of our classes. The fix needs to detect if the body class was created via JSP tag (only one class) or manually (one or more classes).
2.4.0 and 2.5.0 will not introduce nxs at the JSP level so we have quite some time to come up with a nicer fix?