Feature: #82108 - Support EXT: syntax as source in SVG content object

See Issue #82108

Description

The SVG Content Object property src now supports EXT: syntax to reference files from extensions.

page.10 = SVG
page.10 {
   src = EXT:my_extension/Resources/Public/Icons/foo.svg
}

Impact

A SVG file can now be references by EXT: syntax.