Redesign body to make maintenance easier

[anton-matosov]

Current design has a space between top and bottom plates that is used for auxiliary boards.
Even though there are removable sub-plates, its really hard to work with them. Sub-plates cannot really be removed individually, because boards they hold are interconnected into a single circuit.

The current idea is to design 3D printable plates that assemble into an H shape (front view). This will give easy access from the top or the bottom of the robot to all electronics installed