Feature: show email register if user is registered by email

[AndrewZuo01]

Checklist

• I've searched for similar issues and couldn't find anything matching
• I've discussed this feature request in the OpenIMSDK Slack and got positive feedback

Is this feature request related to a problem?

❎ No

Problem Description

I cannot know whether user is registered by email or by phone

Solution Description

add a email register (true) to full user info if user is registered by email

Benefits

then I can separate phone and email login

Potential Drawbacks

No response

Additional Information

No response

[cubxxw]

In the case of domestic users, it is recommended to consider adding an additional option. When logging in via email, a pop-up page can inform them whether they can choose to bind their phone number.