Enhance Image Search Example - Live Update

[par4m]

Enhances Image Search Example by adding Live Update

• Threading: Runs the live updater in the background,separate from FastAPI’s main thread.
• Asyncio: Runs the async updater logic

[badmonster0]

For get_image_caption, we can consider enable cache:

https://cocoindex.io/docs/core/custom_function#parameters-for-custom-functions

[badmonster0]

With this change, the README can also be simplified. We don't need to run cocoindex update separately:

cocoindex/examples/image_search_example/README.md

Line 50 in cbc1998

python main.py cocoindex update

[badmonster0]

Awesome! This example is more fantastics now! Thank you very much!!