feat(tabby): Add model subcommand

[boxbeam]

Closes TAB-472

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 72 lines in your changes are missing coverage. Please review.

Project coverage is 53.54%. Comparing base (8af645b) to head (698b321).
Report is 26 commits behind head on main.

Files	Patch %	Lines
crates/tabby/src/model.rs	0.00%	69 Missing ⚠️
crates/tabby-common/src/registry.rs	0.00%	2 Missing ⚠️
crates/tabby/src/main.rs	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1669      +/-   ##
==========================================
- Coverage   54.02%   53.54%   -0.49%     
==========================================
  Files         115      116       +1     
  Lines        9604     9695      +91     
==========================================
+ Hits         5189     5191       +2     
- Misses       4415     4504      +89     

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[wsxiaoys]

Please enhance the cli usage documents as shared in cmts.

If not coming with better alternative, one example for such cli usage documents can be used for reference is ollama, you can install it to see its cli usage documents.

https://github.com/ollama/ollama?tab=readme-ov-file#list-models-on-your-computer

[boxbeam]

https://github.com/TabbyML/tabby/blob/main/MODEL_SPEC.md