The current `ICON_SMALL_TRI_RIGHT_VEC` uses dark hard-coded colors ([`0.2`, `0.2`, `0.2`])
which makes it impossible to theme and hard to see in dark contexts.
Use `ICON_RIGHTARROW` to match the Outliner's breadcrumbs. This icon uses `TH_TEXT` so it's visible as long as the rest of the text is.
##### Master
(Properties editor background made red on purpose to be able to see the triangle icon)
{F11713038, size=full}
#### This patch
{F11713039, size=full}
Reviewed By: #user_interface, Severin, HooglyBoogly
Maniphest Tasks: T92771
Differential Revision: https://developer.blender.org/D13106