Added postal area update route api

[antoineludeau]

Context

The postal areas data is changing and needs to be updated in our database

Enhancement

This PR adds :

• a new API route PUT /postal-area/district/cog/${cog}

body structure :

[
    {
        "postalCode": "postal code 1",
        "geometry": {
            "type": "MultiPolygon",
            "coordinates": [...]
        }
    },
  {
        "postalCode": "postal code 2",
        "geometry": {
            "type": "MultiPolygon",
            "coordinates": [...]
        }
    },
]

This route will replace the postal areas for an entire district.