feat: Add Circleback connector integration

- Implement CirclebackConnectForm for user input and configuration
- Update connector benefits to include Circleback features
- Add CirclebackConfig component for webhook configuration
- Integrate Circleback into connector selection and management UI
- Update connector constants and document mappings for Circleback

surfsense_web/public/connectors/youtube.svg

@@ -1 +1 @@
-<?xml version="1.0" ?><!DOCTYPE svg  PUBLIC '-//W3C//DTD SVG 1.1//EN'  'http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd'><svg height="100%" style="fill-rule:evenodd;clip-rule:evenodd;stroke-linejoin:round;stroke-miterlimit:1.41421;" version="1.1" viewBox="0 0 24 24" width="100%" xml:space="preserve" xmlns="http://www.w3.org/2000/svg" xmlns:serif="http://www.serif.com/" xmlns:xlink="http://www.w3.org/1999/xlink"><rect height="24" id="Artboard15" style="fill:none;" width="24" x="0" y="0"/><g><path d="M2.093,9.075c0.125,-1.941 1.629,-3.509 3.562,-3.716c2.005,-0.202 4.136,-0.311 6.345,-0.311c2.209,0 4.34,0.109 6.345,0.312c1.933,0.206 3.437,1.774 3.562,3.715c0.061,0.956 0.093,1.933 0.093,2.925c0,0.992 -0.032,1.969 -0.093,2.925c-0.125,1.941 -1.629,3.509 -3.562,3.716c-2.005,0.202 -4.136,0.311 -6.345,0.311c-2.209,0 -4.34,-0.109 -6.345,-0.312c-1.933,-0.206 -3.437,-1.774 -3.562,-3.715c-0.061,-0.956 -0.093,-1.933 -0.093,-2.925c0,-0.992 0.032,-1.969 0.093,-2.925Z" style="fill:#f00;"/><path d="M15.055,12l-4.909,2.995l0,-5.99l4.909,2.995Z" style="fill:#fff;"/></g></svg>
+<svg xmlns="http://www.w3.org/2000/svg" width="256" height="180" viewBox="0 0 256 180"><path fill="#f00" d="M250.346 28.075A32.18 32.18 0 0 0 227.69 5.418C207.824 0 127.87 0 127.87 0S47.912.164 28.046 5.582A32.18 32.18 0 0 0 5.39 28.24c-6.009 35.298-8.34 89.084.165 122.97a32.18 32.18 0 0 0 22.656 22.657c19.866 5.418 99.822 5.418 99.822 5.418s79.955 0 99.82-5.418a32.18 32.18 0 0 0 22.657-22.657c6.338-35.348 8.291-89.1-.164-123.134"/><path fill="#fff" d="m102.421 128.06l66.328-38.418l-66.328-38.418z"/></svg>