Analytics for always_raw preference

[chris13524]

Export metrics on client registrations that enable always_raw so we know % of clients that upgraded to use this new feature

https://github.com/WalletConnect/echo-server/blob/ea1401e818aae6cf7ab0b0819cf4358f2469608b/src/handlers/register_client.rs#L124

[chris13524]

cc @dnul