Evaluation on Segmentation and Depth estimation for backbones

[BrianPulfer]

While instruction for evaluating classification capabilities are well reported, currently, there is no information on how to evaluate pre-trained backbone DinoV2 models on segmentation / detph estimation (i.e. keep the backbone frozen while segmentation / depth estimation head/s are trained and measure metrics).

The closest I got to getting evaluation working was trying to run mmsegmentation/tools/train.py (from version 0.27 of mmseg) on a single node using the configuration for ViTs. This still results in some TypeError.

I would be very grateful if someone could point me in the right direction. I'd also be happy to include this information in the README.