Add typing effect for responses

[codesmith-emmy]

We should implement a typing effect for generated responses to enhance user experience and make conversations feel more natural or human-like.

Generated responses are currently displayed instantly, which feels unnatural. With typing effect, we can simulate the experience of a human typing out responses in real-time.

The typing effect should work as follows:

• When the user sends a message, the response area should display a typing indicator (e.g., three dots or a blinking cursor) to signal that chatbot is "typing" a response.

• The generated response should be revealed character by character or word by word, with slight delay between each character or word, mimicking the typing behaviour of a human.

• Once the entire response is displayed, the typing indicator should disappear.