Release All Models Completed in `auto.imu` and `rank.models` + Obj Update

[coatless]

Issue

The rank.models and the auto.imu functions release only the best models gmwm object. However, there are p more gmwm objects created internal but never surfaced.

Solution

1. Verify that there is no memory constraints with surfacing x64 models.
2. Change output to [[i]][[1]][[1]] to access model comparison table and [[i]][[2]][[p]] to surface a gmwm object.
3. Add a better way of retrieving a model besides in the index approach