Removing SQL_CALC_FOUND_ROWS

[brianhogg]

Description

• Removing SQL_CALC_FOUND_ROWS by building a separate count query off the same table, joins, where.
• Check that SQL_CALC_FOUND_ROWS wasn't added to the query via a filter

Inspired by the approach in WordPress/wordpress-develop#3863 (unmerged due to the risks of the core filters that can modify the query in any way)

Fixes #3079

How has this been tested?

Manually

Checklist:

• This PR requires and contains at least one changelog file.
• My code has been tested.
• My code passes all existing automated tests.
• My code follows the LifterLMS Coding & Documentation Standards.