Calculation of centroid for locations near the 180th meridian (antimeridian) is incorrect

[sergeykad]

The centroid calculation, which simply averages latitude and longitude values, is accurate in most cases, but produces incorrect results near the 180th meridian. For example, with longitudes 179.649556 and -176.131694, the calculation is as follows:

(179.649556 - 176.131694) / 2 = 1.758931

As can be seen, the example produces results in the opposite hemisphere.