Support an end-user friendly OAuthAuthorizationCodeAuthenticator #9
Description
In a perfect world, the AddAuthentication() method for OpenAPI allows some kind of OAuthAuthorizationCodeAuthenticator, which not only should read from the OpenAPI OAuth 2.0 security segment to get the required values, such as these, but also allows for interactive authentication through prompting with the MCP server, allowing for each end-user to use their own credentials.
Eventually, the need to specify authentication on configuration of the server (via AddAuthentication()) should be redundant, since all 'server' values should be specified in the OpenAPI spec (and can be different for each operation!), and all the 'user' values - whether it be a client secret, or a token fetched from interactive credential - should be retrieved from the user.