Add: Add MoveExtJ to the possible movement types

[arjendeetman]

Can be implemetend after the integration of joint targets.

MoveExtJ examples codes:

CONST jointtarget j2 := [[9E9,9E9,9E9,9E9,9E9,9E9], [30,9E9,9E9,9E9,9E9,9E9]];
MoveExtJ j2, rot_ax_speed, z50;

Should set the rob joint values automatically to 9E9.

This an addition to the existing Movement component and baseclass.

[arjendeetman]

Needs a major revision since this is used when an external axis is defined as a separate program task.

A mechanical unit interface is needed. A mechanical unit can be cast from a robot or external axis. Forward kinematics, inverse kinematics, RAPID generator, and Path generator need to be changed to a mechanical unit input instead of a robot input.