[RWI] Change IdentityRequestProvider#request parameter to be an object
This CL changes the real-world-identity API
IdentityRequestProvider#request parameter to be either an object or a
string. This brings the implementation in line with the spec
https://wicg.github.io/digital-credentials/
BUG=341316049
Change-Id: I24011854918f30c552bf80ec7de86b6e2d64b9db
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5546326
Commit-Queue: Peter Kotwicz pkotwicz@chromium.org
Reviewed-by: Nicolás Peña npm@chromium.org
Cr-Commit-Position: refs/heads/main@{#1306476}