Add custom searchbox for cmdpal dock (for the "open command pallete" button)

### Description of the new feature / enhancement

make "open command pallete" button have a search box version (like the taskbar search box)

### Scenario when this would be used?

make last typed thing from command pallete be visible and be continue-able and also makes the command pallete look more native (look winui)

### Supporting information

Start by locating the cmdpal dock implementation and the existing "open command palette" button, then compare its behavior with the taskbar search box described in the issue. Done means the button presents a native-looking search box, preserves the last typed command, and allows that text to be continued.

Written by the indexing model from the issue text.