Initialize model from the start

[skywolf829]

Currently, the model isn't initialized until a dataset is initialized. By default, the model should do the random blob initialization that it currently does for NeRF synthetic data as soon as the server is started. If a SfM dataset is loaded, the UI should ask if the user would like to load the SfM points.

[skywolf829]

Adjusted model loading code to initialize the model to the random blobs it uses for Nerf synthetic training.