Show icon for view tabs when not minimized

### Description

View tabs (e.g. Projects, Output, Watches, etc) only show their icons when they are minimized (rendered by `FlatSlidingButtonUI`). It would be nice, at least for platform applications, to have a setting to allow painting the icon when they are in normal mode (rendered by `FlatViewTabDisplayerUI`).

### Use case/motivation

When there are a number of tabs open it is easier to find the right one when icons are displayed rather than just text. Eclipse and IntelliJ using icons in their tabs.

### Related issues

_No response_

### Are you willing to submit a pull request?

No

Start by reading FlatSlidingButtonUI and FlatViewTabDisplayerUI, the two renderers named in the issue, and trace how view tabs are painted in minimized and normal modes. Identify the existing settings path for platform applications; done means a setting can enable icons for normal view tabs without changing minimized-tab behavior.

Written by the indexing model from the issue text.