Add OAuth token support for GraphQL subscriptions and oauth token revocation for websocket APIs

[dushaniw]

This issue identifies several tasks related to testing GraphQL and websocket APIs in upcoming 4.2.0 release.

• APIM 4.2.0 should terminate websocket connections after the access token is revoked. - https://github.com/wso2-enterprise/wso2-apim-internal/issues/567
• Improvecache lookups in web socket connection and rest API request auth flow. - Lookup invalid token cache before introspection response cache carbon-apimgt#11802
• API-M 4.2.0 should support Oauth token validation during websocket frames. - Since priority is low tracking via Add support for scope validation for Opaque tokens in Websocket and GraphQL subscription APIs #1331

[Tharsanan1]

Task no-1 is resolved with PR: wso2/carbon-apimgt#11780