Add paralax walking and fix walking animation

[1hella]

Closes #57 and #56.

Also added Keine and Player to a parent object in the scene.

[ampaulg]

I feel like I don't agree with the way that only Mokou is have the z axis position adjusted. Imo both characters should do it, especially since they can both walk around the bamboo pile and cauldron.

Also seeing that there it no laundry pole or bamboo pile when I run this branch (but I see them on Main), so double check that nothing weird has happened to the objects

[ampaulg]

The laundry pole, coal pile, and bamboo pile cannot be seen for me when I'm on this branch, it seems like they're "behind" the background. Also the player can walk "in front" of the bamboo stalks if you go north of it, which isn't really right. But if we're gonna block that off later with invisible walls then it's fine

[1hella]

@ampaulg I changed the way the z axis value is calculated now. It's based on the y axis position, i.e. more forward as going south and more backwork as character is going north.

[ampaulg]

looks good