[iOS] Use BlingPrototyping feature in the AI menu

Updates the AI menu from kTest to kBlingPrototyping when using server
inference.

Adds a "name" text field to the AI prototyping menu to allow us to
submit both a name and query to the Bling Prototyping feature, as
defined in the BlingPrototypingRequest proto. The output is also updated to match the "output" field from BlingPrototypingResponse proto.

Bug: 370768381
Low-Coverage-Reason: HARD_TO_TEST
Change-Id: I539b07a2061e07640f53243e0767fa958d0b83d8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5958009
Auto-Submit: Adam Arcaro <adamta@google.com>
Reviewed-by: Joemer Ramos <joemerramos@chromium.org>
Commit-Queue: Adam Arcaro <adamta@google.com>
Cr-Commit-Position: refs/heads/main@{#1374616}