Icons: Harmonize FontAwesome name aliases across codebase
Summary:
Do not use several FontAwesome aliases for the very same font icon but consistently use only one of them.
This may make resolving T16035 a tiny bit easier some day.
* fa-bar-chart-o -> fa-bar-chart
* fa-dashboard -> fa-tachometer
* fa-file-sound-o -> fa-file-audio-o
* fa-file-zip-o -> fa-file-archive-o
* fa-bank -> fa-university
* fa-institution -> fa-university
* fa-image -> fa-picture-o
* fa-photo -> fa-picture-o
* fa-paste -> fa-clipboard
* fa-send-o -> fa-paperplane-o
* fa-toggle-down -> fa-caret-square-o-down
This is not a breaking change for third-parties as the aliases still remain in `webroot/rsrc/css/font/font-awesome.css`.
Closes T16251
Test Plan: Repeatedly grep the codebase for font icons and their several CSS class names defined in `webroot/rsrc/css/font/font-awesome.css`
Reviewers: O1 Blessed Committers, mainframe98
Reviewed By: O1 Blessed Committers, mainframe98
Subscribers: mainframe98, tobiaswiese, valerio.bozzolan, Matthew, Cigaryno
Maniphest Tasks: T16251
Differential Revision: https://we.phorge.it/D26304