gen: Sort waiters, error checks, and lenses in generated output

[endgame]

Same output as https://github.com/brendanhay/amazonka/pull/862, but sticks to HashMap internally to avoid triggering https://github.com/brendanhay/amazonka/issue/888

A couple of enums change value in a strange way, because the generator cannot handle enums-of-numeric values. See https://github.com/brendanhay/amazonka/issues/889