Add render depth in demo and app

[lexiyutou]

This pull request adds support for rendering and visualizing depth maps in the animal mesh rendering pipeline. The changes affect both the Gradio demo (app.py) and the command-line demo scripts (demo.py, demo_tta.py), introducing a new render_depth option throughout the codebase. This allows users to optionally generate and view depth maps alongside the standard outputs.

Depth map rendering support:

• Added a render_depth boolean option to the Gradio interface, example configurations, and demo profiles in app.py, and updated all relevant function signatures and calls to propagate this option. [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11]
• Extended the CLI for both demo.py and demo_tta.py to accept a --render_depth flag, enabling depth map rendering from the command line. [1] [2]
• Implemented logic to render, normalize, and colorize depth maps using the Viridis colormap, and concatenate them to the final output image in both demo scripts. [1] [2] [3]
• Updated the render_and_save function in demo_tta.py to handle the new render_depth argument and produce the colored depth visualization. [1] [2]
• Updated the example shell script (demo_tta.sh) to use the new --render_depth option.