CDRIVER-4638 Remove "Public Technical Preview" from Queryable Encryption Equality API (#1275)

* update libmongocrypt test dependency to 1.8.0

* remove "Public Technical Preview" from QE API for equality

* document MongoDB Server 7.0 is required for Queryable Encryption

* document QE behavior in older MongoDB Server versions

* remove Experiemental from title

* include Manual page at start