Support for "file" / "media" field in product editor

[leewillis77]

The new product editor should support a "file" / "media" field type that allows a user to either select an existing media item, or upload a new one. There are many cases where a plugin may want to extend the product editor to allow users to add/select files on a product, for example

• a product "datasheet" to be attached to a product
• a product user-guide / manual
• a product safety certificate / rating document

[mattsherman]

Thanks @leewillis77 -- I've created an issue for this: #47821

Closing this discussion -- we'll use the issue to track this and refine requirements.