Change "exact match boost" implementation to use a match_phrase query in should

[sarayourfriend]

Problem

We currently use an additional simple query string entry into the boolean filter for search to boost exact phrasal matches on the title of a work:

openverse/api/api/controllers/search_controller.py

Lines 305 to 312 in 50e401f

	quotes_stripped = query.replace('"', "")
	exact_match_boost = Q(
	"simple_query_string",
	flags=DEFAULT_SQS_FLAGS,
	fields=["title"],
	query=f"{quotes_stripped}",
	boost=10000,
	)

Description

We can bypass simple query string altogether for this, saving some parsing cycles in Elasticsearch, and making our intention much clearer in code (and in the generated query), by using match_phrase directly. This also obviates the need to mock out the simple-query-string syntax for phrasal matches.