Refactor collection creation UI (#6485)

* Iteration, before functional component

* Use react-hook-form, shared form for new and edit

* Avoid negative margin on input prefix

* Centered now default for modals

plugins/webhooks/client/components/WebhookSubscriptionListItem.tsx

@@ -25,7 +25,6 @@ const WebhookSubscriptionListItem = ({ webhook }: Props) => {
   const showDeletionConfirmation = React.useCallback(() => {
     dialogs.openModal({
       title: t("Delete webhook"),
-      isCentered: true,
       content: (
         <WebhookSubscriptionRevokeDialog
           onSubmit={dialogs.closeAllModals}