Onboard anomaly-detection plugin to this new authorization mechanism

[DarshitChanpura]

Description

Once the feature is code-complete, the next step would be to show a working PoC by on-boarding a plugin that manages resources. For this we've chosen anomaly-detection.

AD currently performs in-house authorization by extracting users roles and mapping them with roles present for a user on the resource.

This task aims at removing the functions/classes performing in-house authorization to then rely on security plugin to perform resource-authorization.

[DarshitChanpura]

@cwperks Could you please transfer this issue to https://github.com/opensearch-project/anomaly-detection