feat(sms): added support for number pooling

[manchuck]

Description

Motivation and Context

Testing Details

Example Output or Screenshots (if appropriate)

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

[superchilled]

LGTM. Just wondering if it would make more sense to update this test than have a separate test just for this param?

[manchuck]

@superchilled I normally just add new tests for additions. That helps make sure that we are not introducing a BC