Support asp-items for datalist element

The <datalist> element can be used to create a HTML-only "type-to-select" drop-down list (aka combobox with input enabled).

The elements with the <datalist> tag are of type <option>, just like those that would be in a <select> list, which is supported by the asp-items Razor tag helper.

e.g. it would be great to be able to turn

<select asp-for="Customer" asp-items="Customers"></select>

into

<input list="customers" asp-for="Model.Customer" />
<datalist id="customers" asp-items="Model.Customers"></datalist>

But perhaps it would be necessary for the tags to be coalesced into one, so that one need not type out and match the id tag, in which case it might look something like this:

<input asp-for="Model.Customer" asp-items="Model.Customers" />