[feature request] Configurable deadzone & navigate menus with directional pad

[s-ilent]

In the inventory and other menus, when using a controller, the analogue stick is required to move the cursor around. I'd like to suggest some quality of life features.

1. Adjustable deadzone in the ini file

With the controllers I've tested (DualSense and Switch Pro) it seems like the deadzone is low enough to the point where inputs can bounce when the stick is flicked, making menus kind of annoying to navigate.
For modern controllers with looser response curves (and components that degrade quickly), I think allowing the deadzone for menu selections to be configured would be a nice QoL feature.

2. Setting to allow using directional pad in menus

It's a pretty common convention in modern games to use the directional pad to navigate menus alongside the left stick.

However, this would need specific handling for some menus...

• For the inventory, the d-pad is unused.
• For the town tune menu, the d-pad is unused.
• For the town bulletin board menu, the d-pad is unused.
• For the keyboard menu, the d-pad is used to move the cursor.
  Maybe it would make sense to bind the C-stick to moving the cursor in that case, since it isn't used in this menu.
• For the pattern design menu, everything on the controller is used, so I don't think anything can be done here.

^{These were checked against the game manual, not the code itself.}