Upgrade to Font Awesome 6

[S-mardii]

Currently, ODC website is using Font Awesome 4.7

We should update it to the latest version which is Font Awesome 6

[S-mardii]

The following is the documentation provided by the Font Awesome official website:

• https://docs.fontawesome.com/web/setup/upgrade/upgrade-from-v4/#1-locate-and-remove-version-4-assets--references
• https://docs.fontawesome.com/web/use-with/wordpress/install-manually/
• https://docs.fontawesome.com/web/dig-deeper/conflict-detection/

They also provide the official plugin for WP but there are some comments from the users that it is not very useful.