Multiple bug fixes

【Details of fixes】
■【Mac】Fixed a bug in which the thickness of Japanese and European characters were sometimes displayed differently when using some fonts.
■Fixed a bug in the modal display of videos on the top page gallery list, gallery details page, and user details page.
■Corrected the output of quick tags “heading h4” and “heading h5”.

The following are the files that have been modified with this update。
【Modified file】
functions.php
functions/custom_editor.php
functions/head.php
pagebuilder/assets/css/pagebuilder.css
style.css