[AI Assistance] Use mock AIDA client in the panel code

Bug: none
Change-Id: I5443a3de5190b0af6f1565f2761338289421761a
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/6244136
Reviewed-by: Samiya Caur <[email protected]>
Commit-Queue: Samiya Caur <[email protected]>
Auto-Submit: Alex Rudenko <[email protected]>
Commit-Queue: Alex Rudenko <[email protected]>

Author: OrKoN