PROS 4: Rotation Class ctors not explicit

[Richard-Stump]

Task:

The constructors for the rotation class are not declared with the explicit keyword. This will prevent copies or conversions of the class from happening implicitly.

It would be good to check the other device classes to make sure that their constructors are marked with the explicit keyword as well.

Testing:

Make sure implicit copies/conversions do not work:

pros::Rotation rot = pros::Rotation(1); // invalid