Azure: Add OAuth Bearer Token Support

Currently, the CDA product supports several authentication methods, but it does not support OAuth. In order to support the existing authentication methods, like "SharedKey", Azure admins would have to enable settings that they otherwise might have disabled due to corporate policies. OAuth is an industry standard authentication method. In order to do this, the CDA product would need to make a REST API call to retrieve a token and then make a subsequent API call with that token in the authentication bearer header of the call.

An example REST API request for an OAuth Bearer token:

POST https://login.microsoftonline.com/<tenant-id>/oauth2/v2.0/token

Request Body (x-www-form-urlencoded):
"client_id": "<client_id>"
"client_secret": "<client_secret>"
"grant_type": "client_credentials"
"resource_id": "https://storage.azure.com/"
"scope": "https://graph.microsoft.com/.default"

Users would be asked for the values to the various keypairs above OR they would simply need to update the provider file with any necessary keypairs above to be used in the token request. The latter would mean that token requests can be designed by users, rather than forced to conform to something within code.

Sample Response:

{
   "token_type": "Bearer",
   "expires_in": 3599,
   "ext_expires_in": 3599,
   "access_token": "<bearer token>"
}

The CDA product would take the <bearer token> from the "access_token" key above and use it in the authentication header.