Add Support for Phrase Matching

[kevinfodness]

User Story

As a user, I want to be able to enter a phrase in quotes and only see results that match that phrase, e.g., "cool beans" should only match "cool" followed by "beans" rather than each word individually (as is the current default).

Acceptance Criteria

• Add a new method to the controller called enable_phrase_matching that, when called as part of configuration, causes phrase matching to be turned on for all queries that are run through the search implementation.

Implementation Details

Example of how this could be used in code:

add_action(
	'elasticsearch_extensions_config',
	 function( $es_config ) {
		$es_config->enable_phrase_matching();
	 }
);

• When enabled, search queries should be evaluated for text in double quotes, which should be included in the search as a match_phrase.
• Any other text in the search, not in quotes, should be searched for normally.
• The solution should support multiple phrase searches in the same query (e.g., "quick brown" fox "jumped over").
• This feature should be opt-in and should be disabled by default.
• There should be a corresponding disable_phrase_matching function to turn this feature off, which could be used by plugins or themes conditionally to unset this setting in particular contexts (otherwise there would be no way to turn it off once it was turned on).

[mboynes]

We have prior art for this, reach out about that before beginning work on this.

[jakewrfoster]

closed by #67