New section for Command Palette Extensions

### Description of the new feature / enhancement

The command palette could have a dedicated section for its extensions, which has a grid view for easier visualisation and access

### Scenario when this would be used?

In the command palette

### Supporting information

_No response_

Start by locating the Command Palette implementation and its extension UI; the issue names no files, tests, or entry points. Review how extensions are currently presented, then define the dedicated section and grid view as done when extensions are easier to visualize and access from the command palette.

Written by the indexing model from the issue text.