Add ball ground truth emitter and ball positioner

[vincenttumminello]

Includes changes from PR #16 so merge that first.

Also includes changes to the camera intrinsics (#17), merge that first.

Can position the ball from a NUbots_K1 message like:

/// Place the NUSim ball and set its velocity (rt/nusim/ball_command)
message NUSimBallCommand {
    enum Frame {
        /// The simulator world {s}
        WORLD = 0;
        /// The yaw-only frame at the torso's ground projection (x forward, z up), i.e. {r}
        ROBOT = 1;
    }
    Frame frame = 1;
    /// Ball centre; a negative z rests it on the floor at its radius
    vec3 position = 2;
    /// Ball centre velocity
    vec3 velocity = 3;
    /// Ball spin; ignored when rolling is set
    vec3 angular_velocity = 4;
    /// Derive the spin for rolling without slipping from the velocity
    bool rolling = 5;
}

which can be used for simulated games or testing goalie behaviour or other tests.

Adds in code to emit the ball ground truth.

[jpptm]

Address conflict + merge w main, I'll review shortly