[web-php] PR #478: Improve local font-names

Pull Request: https://github.com/php/web-php/pull/478 Author: hakre In 2ceaff53 (Improve fonts support, 2021-11-26) local font names were added but it was still missing a closer review on the previous local /fonts/ prefixed font names which were retained while annotated to be potentially wrong. [#462] Now after review of the [@font-face rule] in the CSS Fonts Module Level 3 W3C Recommendation 20 September 2018 in regard to local(), the following two educated guesses are made: 1. /fonts/ prefixed local() font-names were introduced in the 2014 transition in error and can be removed as those are ineffective, ref 78286b7a (Font URLs are now relative to root; cached.php was breaking the relative URLs., 2014-05-27) 2. local() should have the Postscript name as well as it is "the commonly used key for all fonts on OSX and for Postscript CFF fonts under Windows". [ibid.] Postscript names were obtained with FontForge (20190801), Element -> Font Info... (Ctrl+Shift+F): PS Names -> Fontname. Replace /fonts/Fira/* font-names with their Postscript name. [#462]: https://github.com/php/web-php/pull/462 [@font-face rule]: https://www.w3.org/TR/css-fonts-3/#at-font-face-rule