Add built-in size options for feedback widget, including compact corner mode

Description: As a website admin, I want built-in size presets for the embedded feedback widget (including a compact corner launcher) so that I can deploy a less intrusive experience without relying on custom CSS. Problem: The current widget feels large—as if already opened—and can be intrusive. There is no smaller, corner-sitting version available out of the box. Teams must use custom CSS to shrink or reposition it, which is inconsistent, hard to maintain, and challenging for non-technical admins. Benefit: Reduces visual intrusion by offering a compact launcher that expands on interaction. Delivers consistent, supportable behavior without custom CSS. Improves accessibility and responsiveness with vetted presets. Speeds rollout and reduces setup effort, support tickets, and QA overhead.