Babelfish is hardly the authority on literal translations.
The Italian word che (in which the "ch" is pronounced like the English "k") means, depending on the context, "that", "that which", "what", or even "which".
The word sarà means he/she/it will/shall be. In other words, future tense of third person singular of "to be". That's in Italian again, not in Latin. And it is "sarà", not "sera" (which is Italian for "evening").
Hence, the literal translation is "that which will be, will be" or "what will be, will be". The "whatever shall be, shall be" translation is pretty close to literal.
By the way, the American singer who sings this song does not quite pronounce "sarà" correctly. She swallows the first "a" turning it into a schwa. It should be pronounced clearly as "a", just like the second one. The second one has the grave accent, which means the stress goes on that syllable, and the syllable is short -- the song makes it very long, but I guess that's OK for a song.