[NJR] Side Saddle

This mod replaces the seat animation on the ARR horse mounts, (EX Trial rewards), and Sleipnir. Elezen, already being elegant and side-saddle seated, were not changed, but could easily be adjusted as well should a horse be found which they straddle instead. The replacement comes from the Argos mount in EW content, which appears to always be side-saddle for each tall race. This is better than using a body swap with Elezen, because it is already made for the body proportions, and thereby avoids unnatural stretching to fit the Elezen skeleton. Please let me know what you think, and I will do my best to support updates into the future. Currently supports all tall, (non-popoto) females.