digital_electricity: terminals: multiterminal i/p

wires[] property now contain four components:

• from_component: The component index from which the wire is to be drawn
• from_terminal_no: The terminal number of the above component from which the wire is to be drawn
• to_component: The component index to which the wire is to be drawn
• to_terminal_no: The terminal number of the above component to which the wire is to be drawn

Previously, the wire was only drawn from the 1st terminal of the source
to the 1st terminal of the destination component. Now, we allowed the
user to choose the terminal number of both the source and the
destination component of the wires

Signed-off-by: Rudra Nil Basu <rudra.nil.basu.1996@gmail.com>