Allow for more precise values for sliders

[MicrocontrollersDev]

Currently, sliders that have a great distance between their min and max are impossible to get a specific number with, requiring the user to manually edit their config file and restart their game for it to take effect. Using arrow keys certainly aids in getting a closer number, but because they move by a non-step amount, it doesn't allow for exact values. Similar to the number property type, it should be possible to use shift and control to allow for faster less precise adjustments, leaving an arrow key input with no modifiers to just change the value by one step amount.