Draft commit for review for Popover v11 #1896

[SimpleProgrammingAU]

I spent a couple hours adopting the CDS React approach to the Popover element and it appears to break the previously working approach in CDS Svelte (i.e. without providing a PopoverContent component).

Please have a quick look at what I've done and let me know if we should lean into what looks like a very breaking change or have I missed something that would allow the existing syntax, as shown in the current CDS Svelte documentation, to work?

Implemented:

• added id prop (although, I added that months ago and am now wondering if I added that correctly)
• added dropShadow option
• added containerProps object
• removed references to the relative prop because it looks like that's forced upon you now (or am I misreading the css?)
• amended container to a span element rather than a div per CDS React
• added contentProps to PopoverContent
• amended documentation for new syntax

Not yet implemented:

• tabTip