Add sagemaker option to IntelliChat UI

[IntelliNode]

Intellinode provides a chatbot with Sagemaker llama backend as described in this wiki.

The required work to update the UI with Sagemaker is as follows:

• Add Sagemaker option in the dropbox.
• Display a drop-down list with one selection: llama.
• Display a textbox with url title.

The backend:
When they send a message with SageMaker selection, call the relevant module from intellinode.