[CHA-0] support client-side requests

[kanat]

Slack discussion

• https://getstream.slack.com/archives/C093C61RB16/p1761762054047639?thread_ts=1761761913.659769&cid=C093C61RB16
• https://getstream.slack.com/archives/C093C61RB16/p1761758400671229

Summary

How to use a client-side request:

var response = User.list().
    filterCondition("id", userId).
    withUserToken(userToken). // this is a newly added method to support client-side requests
    request();

CLA

• I have signed the Stream CLA (required).
• The code changes follow best practices
• Code changes are tested (add some information if not applicable)

Description of the pull request