Deprecating Timm

[ashwinvaidya17]

Description

• Currently we support Timm feature extractor. When it has been ascertained that we can use torchfx in otx, timm needs to be removed from the library. The users can use the torchfx feature extractor with timm models.

• With a single class we can also make a couple of changes

  • Include feature maps computation in the feature extractor class (dryrun_find_featuremap_dims)
  • Move _deduce_dims to feature extractor.