Managed Identity/native auth

[svenkerud]

Hi,

This tap looks very promising, and we are looking to deploy it in our system.
However we were wondering if it would be possible to set up authentication with Managed Identity or using native Auth.
As we avoid the use of service principals where possible.

We think it should only require a relative minor change to this method:
https://github.com/Slalom-Consulting/tap-ms-graph/blob/main/tap_ms_graph/auth.py

We are happy to provide a PR with this change, but would like to discuss the design principles regarding how configuration would look with multiple auth options.

Some of our thoughts are:
add use DefaultAzureCredentials = true as an option
add managed Identity ID as an option

We might also need to think about precedence in the case that multiple authentication methods are configured. As well as configuration validation.

Tagging colleague: @hholgersen