Generalize FuzzDataHelper::Read function

To make it easier to use in fuzzers:
- change it not to crash when there is not enough fuzz data left.
- change it to read any trivial object, not just integers

Bug: None
Change-Id: I5dfb47d3accc3c856dfc5d4376676354953d3f27
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/411660
Commit-Queue: Danil Chapovalov <danilchap@webrtc.org>
Reviewed-by: Sam Zackrisson <saza@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#47035}