Add an HTMLElement prop that a Popover can bind to as an alternative to triggeredBy

[magnus-ISU]

Summary

Constructing unique IDs for programmatically created Popovers is annoying.
Ensuring the Popover follows immediately after the item it must bind to is not always possible.
It would be nice if you could pass in a function that returns an HTMLElement, or just an HTMLElement, to the Popover instead of triggeredBy

Basic example

{each htmlelementList as element}
<Popover triggerElement={element}>
{/each}

Motivation

Constructing unique IDs for programmatically created Popovers is annoying and not always simple.