Enhanced authentication for APISIX Dashboard

Current problem

A simple identity authentication module has been implemented in the current panel, which supports the user name/password authentication mode, but its implementation faces some problems.

First of all, in the currently implemented authentication mode, the user name and password are stored in a configuration file in plain text. It does not support hot updates, nor does it support dynamic addition by programs, and it is also difficult to ensure security.

Also, the back-end part currently does not implement an abstract authentication framework specification, and can only implement a single authentication mode, which cannot be extended.

Project Summary

This proposal aims to implement an extensible abstract framework for the front-end and back-end so that it can be extended to other authentication methods while retaining the existing username/password mode and improving it.