Move WebTests web server from Engine/Source/Programs/WebTests/WebServer to Engine/Source/Programs/WebTestsServer, so to make sure not include all files underneath into VS project.
[REVIEW] [at]michael.kirzinger [at]stephen.ma [at]chuck.zhu [at]michael.atchison [at]rafa.lecina
#jira UE-191978
#rb stephen.ma [at]rafa.lecina [at]michael.atchison
[CL 27189120 by lorry li in ue5-main branch]
