Use whiskering for natural transfermations

As per the HoTT book, NTComposeF isn't uniquely determined.

After    | File Name                             | Before
-----------------------------------------------------------
0m39.59s | Category/Equality                     | 0m40.25s
0m18.00s | Functor/Equality                      | 0m17.62s
0m15.73s | NaturalTransformation/Equality        | 0m16.07s
0m11.76s | Comma/CommaCategory                   | 0m11.37s
0m09.51s | Groupoid                              | 0m09.62s
0m07.36s | Category/Morphisms                    | 0m07.51s
0m04.81s | Grothendieck/ToSet                    | 0m04.92s
0m03.92s | Groupoid/Functors                     | 0m03.76s
0m02.35s | Functor/CompositionLaws               | 0m02.24s
0m02.34s | SumPreCategory                        | 0m02.38s
0m01.89s | ProductPreCategory                    | 0m01.86s
0m01.35s | NaturalTransformation/Composition     | 0m02.26s
0m01.12s | InitialTerminalCategory               | 0m01.06s
0m01.11s | NaturalTransformation/CompositionLaws | 0m01.42s
0m00.90s | NatCategory                           | 0m00.94s
0m00.62s | BoolCategory                          | 0m00.64s
0m00.56s | SetCategory                           | 0m00.45s
0m00.31s | Common                                | 0m00.32s
0m00.25s | NaturalTransformation/Identity        | 0m00.28s
0m00.24s | Category/Objects                      | 0m00.24s
0m00.24s | Functor/Composition                   | 0m00.23s
0m00.21s | Category/Core                         | 0m00.18s
0m00.21s | FunctorPreCategory                    | 0m00.29s
0m00.15s | NaturalTransformation/Core            | 0m00.14s
0m00.14s | Category/Duals                        | 0m00.20s
0m00.12s | Functor/Core                          | 0m00.13s
0m00.11s | Peano                                 | 0m00.13s
0m00.10s | NaturalTransformation                 | 0m00.10s
0m00.10s | ComputableCat                         | 0m00.11s
0m00.10s | Category/Category                     | 0m00.10s
0m00.09s | Category/StrictCategory               | 0m00.09s
0m00.08s | Functor/Identity                      | 0m00.12s
0m00.08s | Utf8                                  | 0m00.10s
0m00.08s | DiscreteCategory                      | 0m00.10s
0m00.08s | Functor                               | 0m00.10s
0m00.08s | Grothendieck                          | 0m00.07s
0m00.07s | Notations                             | 0m00.05s
0m00.04s | NotationsUtf8                         | 0m00.06s
-----------------------------------------------------------
2m05.79s | Total                                 | 2m07.50s