Add Ctrl+click form pull-down lists to allow multiple selection

[rafstahelin]

When selecting multiple items, such as Loras or samplers, the current process of individually selecting each item, adding a comma, and repeating can be time-consuming, especially when choosing 10 or 20 items.

I propose implementing a system that allows for multi-selection of items using the standard Ctrl key functionality. This would enable users to select multiple items simultaneously, significantly improving efficiency and reducing the time required for the selection process.

[mcmonkey4eva]

Swarm issues are now tracked at https://github.com/mcmonkeyprojects/SwarmUI