Feature: #61289 - Signal for IconUtility html tag manipulation

See forge#61289


This signal allows to manipulate the rendered html code for a sprite icon by an extension.

Currently all sprite icons are rendered as :code: <span class="">&nbsp;</span>`.

Extensions can now adjust the html tag, add or remove attributes and define own content in between the html tags.


The rendered html code is no longer a span with fixed classes, but can be modified by an extension.