Pull Request to add an overview of all available Font Awesome Icons to the System Information tab.

Summary of Changes

Joomla 3: Icomoon Icons

For Joomla 3 we have a nice overview of all Icomoon Icons that are in the Joomla core: https://docs.joomla.org/J3.x:Joomla_Standard_Icomoon_Fonts
I find that page very useful:

• Users can add such Icons in Articles.
• Extension Developers can use those in their Extensions without adding additional Icon Font Libraries.

Joomla 4: Font Awesome Icons

I needed some default Font Awesome Icons in J4. There wasn't an overview of all Joomla 4 Font Awesome Icons. So I wrote some PHP code to display all the Joomla 4 icons. I used the supplied in the SVGs in /media/vendor/fontawesome-free/webfonts/ to get all the icon glyph names.

The overview that I generated I used to create a J4 "Joomla Standard Font Awesome Fonts" documentation page:
https://docs.joomla.org/J4.x:Joomla_Standard_Font_Awesome_Fonts
However, the documentation page in the Joomla MediaWiki does not support Font Awesome icons and most images are not displayed.

Furthermore I think that it would be useful to have an overview of those Icons in Joomla itself. So that you don't have to visit the documentation website to find some proper icons.

Testing Instructions

After installing this PR a new "Available Icons" tab will be visible:
In System > System Information > "Available Icons" tab

Discussion

• Do other people also think that it would be useful to have an overview of those Font Awesome Icons in Joomla itself?
• Is the "System Information" a suitable place to add such an overview, as only Super Admins have access to that component?. Or would is another place be more suitable?