Add deep thinking section component

[rebeccaalpert]

Design issue: patternfly/patternfly-design-kit#802 (comment)

Design here: https://www.figma.com/design/MSr6kVEOuAxmPOkjg7x8PO/PatternFly-6--Patterns---Extensions?m=auto&node-id=9883-232401&t=H2UeZAM73CQqAvZo-1

We want to use indented expandable content to make this.

Add this to the Message component similar to how we have the sources card and sources API. We want the text to be customizable. Pass down props to any PatternFly components we use. Add a demo to the Bot Messages section of the Messages page and add tests.