feature request: support `Map`

[trim21]

there is no way to serialize a object to int keys like php, js object's keys are always string.

it's possible to present it in js with new Map([[1,'q']]) and hopefully is will became a:1:{i:1;s:1:"q";}

[miso-belica]

Hello, would be nice to consider this addition because there is currently a problem with the order of unserialized array. JS orders numbers in Object by their value when iterating but PHP preserves insertion order. Using Map would solve this problem. For example as and extra option to use it or as a breaking change. The problem is at line 63 in

php-serialize/src/unserialize.ts

Lines 60 to 67 in 1c75a87

	const pairs = parser.getByLength('{', '}', length => unserializePairs(parser, length, scope, options))
	const isArray = pairs.every((item, idx) => isInteger(item.key) && idx === item.key)
	const result = isArray ? [] : {}
	pairs.forEach(({ key, value }) => {
	result[key] = value
	})
	return result

  // this test fails currently
  it('orders correctly', async () => {
    const d1 = unserialize('a:4:{i:5;i:1;i:4;i:2;i:3;i:3;i:2;i:4;}');
    expect(Object.values(d1)).toEqual([1, 2, 3, 4]);
  });

  // I imagine something like this if you don't want to introduce a new major version with backward incompatibility
  // this is just one of many possibilities, important is to get ordered items back
  it('orders correctly using map', async () => {
    const d1 = unserialize('a:4:{i:5;i:1;i:4;i:2;i:3;i:3;i:2;i:4;}', {}, {toObject: 'object' | 'map' | 'pairs'});
    expect([...d1.values()]).toEqual([1, 2, 3, 4]);
  });

I see there is a PR #292 already to support Map. Maybe it could be incorporated there?

[steelbrain]

Fixed by #292