Resolve "Make new button style, SP=2"

TODO

Determine property name

The issue refers to some as-yet unknown property:

It is supposed to triggerable by an upcoming property of Actions. (e.g. this could be a new class, and in the future if we get an action with the new propetry, we could just automatically add that new class)

As the issue doesn't go into detail as to what this property is, or when it would be set to true, I've just called it TEMP_OUTLINE_PROPERTY for now.

This should be renamed when we know what it should be called

Testing

Add the property TEMP_OUTLINE_PROPERTY: true to an action that's given to an action-button that you want to see with the outline style

Closes #1072 (closed)