Fix `distance_to_polyline` function in `position.rs`

The current implementation uses geo:0.27 euclidean distance to get the distance between a point and a "polyline" object composed of several positions

The implementation has been here due to refactoring adaptation to the new Positionstruct and testing it is required

Problem is that the following unit tests fail
Is it dues to data or implementation ?

    macro_rules! test_distance_to_line {
        ($test_name:ident, $position:expr, $line:expr, $expected:expr) => {
            #[test]
            fn $test_name() {
                let epsilon = 1e-7;

                let distance = distance_to_line(&$position, $line);
                let delta = (distance - $expected).abs();

                assert!(
                    delta <= epsilon,
                    "Actual: {} (expected: {}",
                    distance,
                    $expected
                );
            }
        };
    }
    test_distance_to_line!(
        fifty_meters_north,
        position_from_degrees(48.62564545754, 2.24150940001, 0.),
        &[position_from_degrees(48.62519582726, 2.24150938995, 0.),
            position_from_degrees(48.62519580005, 2.24175355955, 0.)],
        50_f64
    );
    test_distance_to_line!(
        eigthen_meters_east,
        position_from_degrees(48.62519580005, 2.24175355955, 0.),
        &[position_from_degrees(48.62519582726, 2.24150938995, 0.),
            position_from_degrees(48.62564545754, 2.24150940001, 0.)],
        18_f64
    );

Start in position.rs by locating distance_to_polyline and the related distance_to_line tests shown in the issue. Run the failing unit tests and inspect how geo 0.27 calculates Euclidean distance with the refactored Position type. Done means determining whether the test data or implementation is wrong and making the tests pass with the expected distances.