Add ability to get registered data

[apih]

This PR adds the ability to get registered data in Alpine.data(). This will allow a use case like this:

Alpine.data('Component1', {
  // bla bla
});

Alpine.data('Component2', {
  // bla bla
});

Alpine.data('Component3', {
  ...Alpine.data('Component1'),
  ...Alpine.data('Component2'),
});

[ekwoka]

You can just do that in the x-data

x-data="{...Component1, Component2}"

Just know this will break getters/setters

Also,

Alpine.data('Component3', () => {
   ...this.Component1(),
   ...this.Component2()
})

with

x-data="Component3"

should actually work (and still break getters/setters)

a utility component liek

Alpine.data("merge", (...components: object[]) => {
    return components.reduce((acc, obj) => {
      Object.defineProperties(acc, Object.getOwnPropertyDescriptors(obj));
      return acc;
    }, {});
  });

can be nice to merge components similar to spreading, but maintaining getters and setters, and this references, and such.

[apih]

I am not aware that getters and setters will break when merged using spread operator. Mainly because I rarely use getters and setters. Will need to be careful in the future then.

[ekwoka]

Yeah, it makes sense when you think about it. If you enumerate the properties and values on an object, getters won't be getters, they will be the key and the value got from running that getter at that moment.

similarly, setters aren't enumerable at all.

the defineProperties method actually finds out the full description of the property (enumerable? configurable? read only? getter? setter?) and replicates all of that to the new object.

[calebporzio]

Good insight @ekwoka - thanks!