Add create_recovery_token method

Add a convenience function that performs most of the worked laid out in the "Password Recovery Tokens" section of the data control platform guide. This function should take a password, generate a key, encrypt it, and return the key as a recovery token for display to an end user and the encrypted password (with iv on the front) for storage by the caller.

Read the "Password Recovery Tokens" section of the Data Control Platform guide first, then locate the Rust SDK entry points for key generation and password encryption. Implement the convenience method with the specified token and IV-prefixed encrypted-password outputs, and verify its behavior against the guide's workflow.

Written by the indexing model from the issue text.