[CmdPal] Outline icons for custom CmdPal menus

### Description of the new feature / enhancement

Having colorful icons in CmdPal's menus/options feels confusing, especially since some use the exact same icon but at different sizes (e.g., Calculator).

My proposal is to return to Run's philosophy and use outlined icons, and this way, easily differentiate between CmdPal's own options/commands and regular Windows apps.

### Scenario when this would be used?

Main search

### Supporting information

_No response_

Start at CmdPal's main search and inspect how custom menu and option icons are currently presented. Compare the existing colorful icons with the outlined-icon proposal in the issue; done means CmdPal's own menu options are visually distinguishable from regular Windows app icons without confusing size or style differences.

Written by the indexing model from the issue text.