[FedCM] Allow arbitrary data as parameters instead of string/string pairs
As mentioned in the updated spec:
https://w3c-fedid.github.io/FedCM/#dom-identityproviderrequestoptions-params
https://w3c-fedid.github.io/FedCM/#ref-for-dom-identityproviderrequestoptions-params%E2%91%A0
Bug: 374073124
Change-Id: If828c00da8f89c6ea2b3724db0d75ed2eea2591c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5990590
Reviewed-by: Dominic Farolino dom@chromium.org
Commit-Queue: Christian Biesinger cbiesinger@chromium.org
Reviewed-by: Yi Gu yigu@chromium.org
Cr-Commit-Position: refs/heads/main@{#1380612}