Client Playground

[PascalSenn]

In a dev environment you often need to be able to create access tokens. To generate these access tokens you must execute the authentication flow with the specific grant type of a client. To get an access token you currently must create a custom secret to be able to fetch a token. It would be helpful if IdOps had a client playground where you can verify that a client works correctly and that you can fetch a token.

1. We need to be able to configure a client to "work" with the idops client playgorund. This should be just a flag that you can toggle in the client settings. This flag adds a secret which is not displayed in the UI under secrets and also add the redirect url of idops to the allowed redirect urls.
2. The playground: The playground should have a dropdown which flow should be executed on the client. With a click on play, you should be able to fetch the access token. If possible also userinfo should be fetched. The token should then be displayed in it's base64 format and maybe also like jwt.io does it to inspect the claims in the token
3. The flows
   3.1 Authroization Code Flow: We add redirect url https://idopsurl/client-signin-redirect. We encode the client id in the state value of the authorize request, and therefore get it back on the callback from the identity server. We then store the received token in the local storage and redirect the user to the Client playgorund (and display the token)
   3.2 Client Credentials: We request the token and display in in the Client.Playground