CopilotChat.nvim blink cmp integration

### Is your feature related to a problem?

_No response_

### Describe the new feature

Would be cool to add blink cmp integration to the copilot chat pack

https://github.com/CopilotC-Nvim/CopilotChat.nvim/discussions/969#discussioncomment-13497349

### Additional context

_No response_