Add support for address tag to group block

[benoitchantre]

What problem does this address?

The address tag would be a nice addition to add more semantic to contact information.
Use cases: contact page, footer.

What is your proposed solution?

Add an address tag option to the HTML elements that can be used with the group block

[carolinan]

In my opinion, this tag should not be exposed to users in the interface because it is not common enough for users to benefit from having it in the short list of allowed tags.
Developers can already use this tag with any block that supports the tag name attribute. For situations where a site owner needs to be able to add this more frequently than usual, there is already the option to create it as a pattern with the correct tag set.