Run PHP-CS-Fixer to clean up style issues and unused code

This PR does not change any logic, and is just house cleaning of the current code.

PHPCS was run with the following fixers: indentation, linefeed, trailing_spaces, return, braces, php_closing_tag, extra_empty_lines, controls_spaces, eof_ending, include, elseif, unused_use, visibility, short_tag