Cleanup error message

[mrleblanc101]

Hi,
Would it be possible to cleanup the error messages of the forward function ?

throw new TypeError('forward did not receive an array');
throw new TypeError('forward received an array of strings, but it only accepts an array of numbers.');
throw new TypeError(`forward received an invalid longitude of ${lon}`);
throw new TypeError(`forward received an invalid latitude of ${lat}`);
throw new TypeError(`forward received a latitude of ${lat}, but this library does not support conversions of points in polar regions below 80°S and above 84°N`);

If you look at thetoPoint function, the error messages are much cleaner.

throw new Error(`MGRSPoint bad conversion from: ${mgrsString}`);
throw new Error(`MGRSPoint bad conversion from ${mgrsString}`);
throw new Error(`MGRSPoint zone letter ${zoneLetter} not handled: ${mgrsString}`);
throw new Error(`MGRSPoint has to have an even number of digits after the zone letter and two 100km letters - front half for easting meters, second half for northing meters ${mgrsString}`);

Here is what I propose:

// LatLong
throw new TypeError('LatLong: Did not receive an array');
throw new TypeError('LatLong: Received an array of strings, but expect an array of numbers.');
throw new TypeError(`LatLong: Received an invalid longitude of ${lon}`);
throw new TypeError(`LatLong: Received an invalid latitude of ${lat}`);
throw new TypeError(`LatLong: Received a latitude of ${lat}, but does not support conversions of points in polar regions below 80°S and above 84°N`);

// MGRS
throw new Error(`MGRS: Bad conversion from: ${mgrsString}`);
throw new Error(`MGRS: Bad conversion from ${mgrsString}`);
throw new Error(`MGRS: Zone letter ${zoneLetter} not handled: ${mgrsString}`);
throw new Error(`MGRS: Expect an even number of digits after the zone letter and two 100km letters - front half for easting meters, second half for northing meters ${mgrsString}`);

[mrleblanc101]

I don't mind opening a PR for this

[mrleblanc101]

Maybe we don't need the MGRSPoint and forward (or the proposed MGRS:, LatLong:) prefix at all inside the error message.
We know it's a LatLong conversion error because we called forward().
And we know it's a MGRS conversion error because we called toPoint().

So i propose this:

// LatLong
throw new TypeError('Expected an array of numbers');
throw new TypeError('Received an array of strings, expected an array of numbers');
throw new TypeError(`Received an invalid longitude of ${lon}`);
throw new TypeError(`Received an invalid latitude of ${lat}`);
throw new TypeError(`Received a latitude of ${lat}, but does not support conversions of points in polar regions below 80°S and above 84°N`);

// MGRS
throw new Error(`Bad conversion from: ${mgrsString}`);
throw new Error(`Bad conversion from ${mgrsString}`);
throw new Error(`Zone letter ${zoneLetter} not handled: ${mgrsString}`);
throw new Error(`Expected an even number of digits after the zone letter and two 100km letters - front half for easting meters, second half for northing meters ${mgrsString}`);