Feature: Data type creation (#645)

* split data type handlers into multiple files

* return promise

* test register root as same entity as items

* add insert method to entity db

* redirect to new data type when selecting in options modal

* add options to modal name

* Update manifests.ts

* add margin to data type info view

* fix import

* update with models from server

* push new item to tree

src/Umbraco.Web.UI.Client/libs/workspace/context/workspace-context.interface.ts

@@ -13,4 +13,5 @@ export interface UmbWorkspaceContextInterface<DataType = unknown> {
 	destroy(): void;
 	// TODO: temp solution to bubble validation errors to the UI
 	setValidationErrors?(errorMap: any): void;
+	save(): void;
 }