Notify about missing project Qt version and provide means to set the default Qt version for the project

As far as I can tell, everything is set the way it is supposed to be.  Every single Qt header in my code has a not found error within my VS project which results in over 230 errors.  Last time I worked on this project (with Qt 5.12 on VS 2017) I was able to build it.  I tried adding the direct path to the "include" directory in both the C++ Additional Include directories and "Additional Qt Header Search Paths" and that didn't fix it.