Icons to load for ProgressIndicator

[sherpal]

Context: if a ProgressIndicator is used with a ValueState different from the default, there is an icon appended to the ProgressIndicator, but it had to be loaded.

IS: currently we don't make it so that the icon is automatically loaded, so we get errors and warnings in the console when using ProgressIndicator.

SHOULD: when using value state of a ProgressIndicator, automatically add the icons. The icons to load are: "hint", "status-positive", "status-critical" and "status-negative"