feat: addded default appRoot selector from appComponent
feat: addded default appRoot selector from appComponent

When no appRoot is given in the preboot options, the selector for the appcomponent to render is used as the appRoot for the clientscript for preboot.

angular/universal,jeffwhelpley/universal,jeffwhelpley/universal,ufo-github/universal,angular/universal,ufo-github/universal,manekinekko/universal,manekinekko/universal,ufo-github/universal,angular/universal,angular/universal