[Workspace] Add duplicate saved objects API (opensearch-project#6288) (…

…#326)

* Add copy saved objects API



* Modify change log



* Add documents for all saved objects APIs



* Revert the yml file change



* Move the duplicate api to workspace plugin



* Modify change log



* Modify api doc



* Check target workspace exists or not



* Remove unused import



* Fix test failure



* Modify change log



* Modify workspace doc



* Add more unit tests



* Some minor change



* Fix test failure



* Modify test description



* Optimize test description



* Modify test case



* Minor change



---------

Signed-off-by: gaobinlong <gbinlong@amazon.com>

src/core/server/saved_objects/routes/index.ts

@@ -45,7 +45,6 @@ import { registerExportRoute } from './export';
 import { registerImportRoute } from './import';
 import { registerResolveImportErrorsRoute } from './resolve_import_errors';
 import { registerMigrateRoute } from './migrate';
-import { registerCopyRoute } from './copy';
 
 export function registerRoutes({
   http,
@@ -72,7 +71,6 @@ export function registerRoutes({
   registerExportRoute(router, config);
   registerImportRoute(router, config);
   registerResolveImportErrorsRoute(router, config);
-  registerCopyRoute(router, config);
 
   const internalRouter = http.createRouter('/internal/saved_objects/');