Merge release v0.20

[1runeberg]

New Features:

• Add LlamaCpp support
• Streaming responses can now be cancelled
• Add more visible indicator that LLM request is processing
• Polished responsiveness aand indicators dure LLM request processing
• New error handling snackbars for REST API errors/issues

Fixes:

• Fixed image rendering when chat session is loaded from disk
• Fixed image previews when using for attach button instead of drag and drop
• Fixed issue with encryption key confirmation succeeding if confirmation box is empty

Updates:

• Minor Readme update (capitalization on "Compiling on your Own"