[5.7] Refactor FoundationApplicationTest.php (#25813)
[5.7] Refactor FoundationApplicationTest.php (#25813)

* Remove unnecessary fully qualified class names and use ::class

* Replace ServiceProviderForTestingThree with two anonymous classes.
For normal bindings, assert that a different instance is resolved each time.

* Fix StyleCI issues

tjbp/framework,vlakoff/framework,bytestream/framework,cybercog/framework,arturock/framework,arturock/framework,barryvdh/framework,mul14/laravel-framework,laravel/framework,stidges/framework,stevebauman/framework,crynobone/framework,morrislaptop/framework,cybercog/framework,tjbp/framework,tjbp/framework,cviebrock/framework,hafezdivandari/framework,gms8994/framework,tomschlick/framework,hafezdivandari/framework,JosephSilber/framework,notebowl/laravel-framework,JamesForks/framework,dwightwatson/framework,ChristopheB/framework,morrislaptop/framework,samlev/framework,srmkliveforks/framework,driesvints/framework,rodrigopedra/framework,bytestream/framework,ChristopheB/framework,jerguslejko/framework,mul14/laravel-framework,cviebrock/framework,stidges/framework,jerguslejko/framework,lucasmichot/framework,vlakoff/framework,tomschlick/framework,srmkliveforks/framework,ChristopheB/framework,crynobone/framework,stevebauman/framework,srmkliveforks/framework,JosephSilber/framework,cviebrock/framework,barryvdh/framework,leo108/laravel_framework,jerguslejko/framework,mul14/laravel-framework,rodrigopedra/framework,barryvdh/framework,samlev/framework,notebowl/laravel-framework,leo108/laravel_framework,laravel/framework,halaei/framework,srmkliveforks/framework,cybercog/framework,gms8994/framework,vlakoff/framework,jerguslejko/framework,JamesForks/framework,tomschlick/framework,driesvints/framework,dwightwatson/framework,arturock/framework,mul14/laravel-framework,barryvdh/framework,gms8994/framework,stidges/framework,stidges/framework,halaei/framework,halaei/framework,cviebrock/framework,rodrigopedra/framework,lucasmichot/framework,rodrigopedra/framework,gms8994/framework