Added maintenance for image cache and handler for HTTPS OmniServer APIs

[colinmurphy326]

1. Image Cache

   • Added function to clear screnshot_*.png files from the image cache directory
   • Triggers every time a user clicks the "clear" button on the chatbot history

2. HTTPS OmniParser Server Endpoints

   • Relaxed the mandate for running unsecured on HTTP
   • The HTTPS server we tested on required a trailing "/" on /parse/ and /probe/ as well
   • Gradio now attempts both on HTTP first, then tries HTTPS with trailing slash

3. Transformers version

   • The latest version of transformers (4.50.0) is not compatible
   • Fixing to 4.45.0 enables running the Omni stack

[colinmurphy326]

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