feat support reverse proxy

[wonyx]

Summary

fixed #177

This pull request introduces the WithTrustForwardedHeader option to the NewLogtoClient constructor. When this option is set to true, the Logto client will trust X-Forwarded-* headers (e.g., X-Forwarded-Host, X-Forwarded-Proto) to correctly construct the request's origin URL.

This is particularly useful for applications running behind a reverse proxy or load balancer, ensuring that redirect URIs for the sign-in and sign-out processes are generated with the correct public-facing scheme and host.

Usage example

logtoClient := client.NewLogtoClient(
	logtoConfig,
	storage,
	client.WithTrustForwardedHeader(true),
)

Testing

added unittest cases.

Also I have been tested it in firebase hosting with cloud run environment that described in #177 .

Checklist

• [ ] .changeset
• unit tests
• integration tests
• [ ] necessary TSDoc comments