Refactor panther_azuresignin_helpers.actor_user to use imported deep_get

[ben-githubs]

Background

This function is called from within the Azure.Signin data model code. Data models don't operate on a full Panther Event obejct, but instead get passed an immutable dict, which doesn't have a deep_get function as an attribute. For this function to work inside a data model, we need to refactor to use the imported deep_get from panther_base_helpers.

Changes

• Update panther_azuresignin_helpers to import deep_get from panther_base_helpers
• Adjust panther_azuresignin_helpers.actor_user to use imported deep_get instead of event.deep_get.

Testing

• Wrote an Azure.Signin test rule that used event.udm("actor_user") and confirmed it returned expected result without error
  • test rule is not included in PR

[github-actions]

😱
looks like some things could be wrong with the packs

[INFO][root]: ignoring file dependabot.yml