Is your feature request related to a problem? Please describe.
When playing with KB / Mouse and the user inventory is open, you can double click to gather all like items into a stack

Describe the solution you'd like
Whatever controller keybind represents "pick up item / stack" should be able to double press and gather all like items. For example, if you have a 32 stack of cobble and a 10 stack of cobble. Double press on one of those stacks to form a single 42 stack.

Describe alternatives you've considered
using a mouse
i wouldn't mind a different dedicated keybind for this action
using another mod altogether (Controllable is my go-to but not supported for MC 1.20.4)