Fix install.py for compatibility with modern Python, pip, and SD environments

[palentir]

Summary of Changes:

• Rewrote install.py to eliminate deprecated and unstable dependency logic
• Replaced pkg_resources checks (deprecated in setuptools ≥70) with direct pip subprocess installs
• Removed unused dependency: wandb (telemetry, not required by this extension)
• Simplified and stabilized dependency list (fastai, tensorboardX, ffmpeg-python, yt-dlp, opencv-python, Pillow)
• Improved error handling during dependency installs (continues even if one fails)
• Ensured model download logic remains intact and safer with clear progress display
• Prevented recursive dependency resolver conflicts (NumPy, Pydantic, Thinc issues)
• Modernized code style and docstrings for clarity and maintainability

Why This Fix Is Needed

• The old script breaks on Python ≥ 3.10 and pip ≥ 24 due to deprecated pkg_resources calls
• Causes AttributeError: _DistInfoDistribution__dep_map and FileNotFoundError for numpy.dist-info
• Leads to repeated dependency downgrade loops that break Stable Diffusion Forge/A1111 environments
• This version ensures smooth, conflict-free setup under CUDA and modern SD builds

Tested Environment

• Python 3.10 (Conda)
• CUDA 11.8 / Torch 2.0.1
• Stable Diffusion A1111 v1.5.1 and Forge (latest)
• Ubuntu 22.04 LTS (WSL2)