AWS components: Enable AWS IAM roles to work with IAM users

Today, users can use either an AWS IAM role using a pod identity or an IAM user configured through a Dapr component.

For some cases it's best to mix and match both.

Reference: https://docs.aws.amazon.com/sdk-for-go/api/aws/session/

Start with the AWS SDK for Go session reference linked in the issue, then inspect the AWS components that currently support pod-identity IAM roles or IAM users. Identify the components in scope and define done as allowing both credential approaches to work together, with appropriate coverage for the combined configuration.

Written by the indexing model from the issue text.