Added support for MobileSAM for snappier Gradio experience

[JunkyByte]

I have added support to MobileSAM which can be used to experience a snappier Gradio interface as it runs faster on cpu than the original SAM.

During tracking it does not impact much, especially on CUDA.

I have removed args.device = "cuda:3" in app.py as it prevents from correctly selecting devices when running the script.

This adds MobileSAM as a requirement.

[yclicc]

This is great, but there are two bugs. 1, in your requirement.txt the new line that installs MobileSAM shouldn't have "pip install" in it. 2. in app.py you haven't set the SAM_checkpoint_url_dict value for the new vit_t, so it doesn't know where to download it from (maybe solve by adding an instruction to manually download it).