Multiple bug fixes

【Contents of the fix】
■Corrected a display bug on the password protection page when “Content leading to membership registration” is not selected.
■Changed the date notation of the top page news ticker.
■Fixed a symbol that was not output correctly in the custom CSS.
■Fixed a bug in which drop-down grandchild menu items were not displayed properly.
■Social Button Type 5 (Official Button) “Facebook Like Button” specification change support.

The following are the files that have been modified for this update.

【Modified file】
functions/head.php
functions/password_form.php
header.php
style.css
template-parts/sns-btn-btm.php
template-parts/sns-btn-top.php