spring-security5-oauth2-client-server

OAuth2 client server example with PKCE and without PKCE with Spring Security 5.7.1 Version

##Features supported

1. Springboot OAuth2 server without pkce
2. OAuth2 client without pkce
3. Springboot OAuth2 server with pkce
4. OAuth2 client with pkce
5. Springboot OAuth2 server with pkce with refreshtoken support (by default sprint security does not support it)