What problem does this solve or what need does it fill?

Sometimes, all of the inputs of a given type need to be reset at once.

What solution would you like?

Add a Input::reset_all method.

What alternative(s) have you considered?

Manually set the Input<T> resource to its default value.

E.g.

*keyboard_input = Input::<KeyCode>::default();

Additional context

Used in a workaround for #1700, as documented in https://bevy-cheatbook.github.io/programming/states.html#with-input