Improve readability of the new WCS exceptions
Improve readability of the new WCS exceptions

Co-authored-by: Mihai Cara <154d2b01404a765095b80c77bdac8a6b5c4fb605@users.noreply.github.com>
astropy/astropy,saimn/astropy,StuartLittlefair/astropy,lpsinger/astropy,saimn/astropy,lpsinger/astropy,astropy/astropy,mhvk/astropy,pllim/astropy,StuartLittlefair/astropy,larrybradley/astropy,saimn/astropy,StuartLittlefair/astropy,pllim/astropy,larrybradley/astropy,mhvk/astropy,saimn/astropy,larrybradley/astropy,larrybradley/astropy,astropy/astropy,larrybradley/astropy,StuartLittlefair/astropy,lpsinger/astropy,pllim/astropy,pllim/astropy,lpsinger/astropy,mhvk/astropy,lpsinger/astropy,StuartLittlefair/astropy,astropy/astropy,astropy/astropy,saimn/astropy,mhvk/astropy,pllim/astropy,mhvk/astropy