[Improvement] Use AMAZON.FallbackIntent Intent to disambiguate unexpected responses

[TheDreamSaver]

The AMAZON.FallbackIntent is considered when the user's spoken input cannot be matched with confidence to any of the other intents in the skill.

Also, Amazon just released the capabilities to adjust AMAZON.FallbackIntent's sensitivity which makes it much more useful than it was ever before.
https://developer.amazon.com/en-US/docs/alexa/custom-skills/standard-built-in-intents.html#adjust-sensitivity

Making this enhancement to our Alexa skill will require knowledge of handling exceptions in a conversational way and utilizing the built-in Fallback Intent. Research its feasibility and check which sensitivity settings works the best with our model. Testing must be done on an actual device for this intent.