Set against the backdrop of a hit dating competition show, “UnREAL” is led by Rachel, a young staffer whose sole job is to manipulate her relationships with and among the contestants to get the vital dramatic and outrageous footage the program’s dispassionate executive producer demands. What ensues is a humorous, yet vexing, look at what happens in the world of unscripted television, where being a contestant can be vicious and producing it is a whole other reality.