Fenced frames: Rename fenced frame local unpartitioned data access to
fenced storage read.

This CL renames fenced frame local unpartitioned data access API to
fenced storage read API. It does not change any behavior except the
error messages when the API is called without attestation or without
network revoked.

This CL also renames the proto enum for this API. It is safe to do so
because there has been no attestation list containing this API shipped.

Bug: 375607722
Change-Id: Iab24e4226fc698ff5b3c1afa6ad5f4da464914ac
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5966637
Reviewed-by: Avi Drissman <avi@chromium.org>
Reviewed-by: Shivani Sharma <shivanisha@chromium.org>
Reviewed-by: Fiona Macintosh <fmacintosh@google.com>
Reviewed-by: David Vallet <dvallet@chromium.org>
Commit-Queue: Xiaochen Zhou <xiaochenzh@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1378084}