Remove the need of a carrier phrase for AMAZON.SearchQuery

According to https://developer.amazon.com/docs/custom-skills/slot-type-reference.html#searchquery,

each sample utterance must include a carrier phrase.

This leads to problems with Skill invocations for certain Skills. A dictionary cannot be invoked with "Alexa, ask Skill for query". Also it makes some In-Skill conversations harder or awkward.

There have already been requests for this:

Uservoice:

• https://alexa.uservoice.com/forums/906892-alexa-skills-developer-voice-and-vote/suggestions/34248877-remove-the-requirement-for-a-leading-phrase-with-a

Amazon Developer Forums:

• https://forums.developer.amazon.com/questions/179005/how-to-catch-everything-the-user-is-saying-without.html
• https://forums.developer.amazon.com/questions/200957/can-we-use-amazonsearchquery-without-using-search.html
• https://forums.developer.amazon.com/questions/167888/is-there-way-to-capture-the-complete-utterence-in.html
• https://forums.developer.amazon.com/questions/170421/objective-get-full-user-utterance-approach-amazons.html
• https://forums.developer.amazon.com/questions/167363/amazonsearchquery-not-working.html
• https://forums.developer.amazon.com/questions/178061/problem-with-getting-full-text-from-alexa.html
• https://forums.developer.amazon.com/questions/216085/how-to-get-free-form-speech-text-input.html
• https://forums.developer.amazon.com/questions/175579/is-there-a-way-to-retrieve-the-user-query-in-a-unh.html?childToView=178705#comment-178705
• https://forums.developer.amazon.com/questions/8765/slot-wildcards.html

Skill with this problem: https://github.com/petergtz/alexa-wikipedia/issues/68