Integrate SDDS base theme link component with XB

Icon prop and icon placement prop works for megaphone. There's a glitch where it gets greyed out when props are messed with. Link opens weird.

It would be good to do a side-by-side comparison with Storybook to see if it matches:

https://uikit.civictheme.io/

And ideally record the testing of all the props so we can see where the issues are to determine if the issues are on our end or on the XB end.