Setting addExtension to default to false

[TophrC-dd]

What does this PR do?

This pr sets the parameter addExtension to default to false.

Motivation

Because this parameter requires additional parameters to operate. it can cause issues to existing workflows where the user might not intend to add the extension layer.

This addresses #133

Testing Guidelines

Wrote tests that operate through the various configurations.

Additional Notes

Types of changes

• [x] Bug fix
• [ ] New feature
• [ ] Breaking change
• [ ] Misc (docs, refactoring, dependency upgrade, etc.)

Check all that apply

• [ ] This PR's description is comprehensive
• [ ] This PR contains breaking changes that are documented in the description
• [ ] This PR introduces new APIs or parameters that are documented and unlikely to change in the foreseeable future
• [ ] This PR impacts documentation, and it has been updated (or a ticket has been logged)
• [ ] This PR's changes are covered by the automated tests
• [ ] This PR collects user input/sensitive content into Datadog