Refactor ProjectGroupDropdown component and schema

Signed-off-by: Niek Rossen <niek.rossen@infosupport.com>

plugins/octopus-deploy/src/index.ts

@@ -16,6 +16,7 @@
 export {
   octopusDeployPlugin,
   EntityOctopusDeployContent,
+  OctopusDeployDropdownFieldExtension,
   isOctopusDeployAvailable,
 } from './plugin';
 

plugins/octopus-deploy/src/plugin.ts

@@ -66,6 +66,7 @@ export const EntityOctopusDeployContent = octopusDeployPlugin.provide(
   }),
 );
 
+/** @public */
 export const OctopusDeployDropdownFieldExtension = octopusDeployPlugin.provide(
   createScaffolderFieldExtension({
     name: 'OctopusDeployProjectGroupDropdown',