[FR] Send password reset email function

**Is your feature request related to a problem? Please describe.**
Via `firebase_admin_auth` I'm able to create and manage users. When I want to generate a password reset email through the default Firebase functionality (Firebase sends the email), I'm not able to do this through the Admin SDK, as only `generate_password_reset_link` is supported. I have to resort to sending a REST API call instead.

**Describe the solution you'd like**
Support a `send_password_reset_email` function that sends an email via Firebase to reset her password, similar to the Node.js client.

**Describe alternatives you've considered**
Sending a REST API call through HTTP.