Pass form prop to input so it works even if the select is ouside the form tag

[zvin]

Hello!

When using CreatableSelect outside of a form passing it a form prop, this prop is not passed to the created input resulting in the field not being submitted as part of the form.
This PR fixes it.

My problem was with CreatableSelect but it might fix other use cases as well.

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🦋 Changeset detected

Latest commit: 0e43b00

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Name	Type
react-select	Patch

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[zvin]

Using a regular select will submit the myField value.

<div>
  <form action="/someAction" id="myForm">
    <input type="submit" />
  </form>
  <select form="myForm" name="myField">
    <option value="x">X</option>
    <option value="y">Y</option>
  </select>
<div>

Using React-Select, it won't.

<div>
  <form action="/someAction" id="myForm">
    <input type="submit" />
  </form>
  <Select form="myForm" name="myField" options={[{ value:"x", label: "X" }, { value:"y", label: "Y" }]} />
<div>

This PR fixes it.