Spaces - Migrate to NP Saved Objects Service (#58716)

* use NP saved objects service for type and wrapper registration

* simplifying

* additional testing

* revert snapshot changes

* removing dependency on legacy saved objects service

* consolidate mocks

* fixing imports

* addrress PR feedback

* remove unused docs

* adjust tests for updated corestart contract

* address test flakiness

* address flakiness, part 2

* address test flakiness

Co-authored-by: Elastic Machine <elasticmachine@users.noreply.github.com>

x-pack/legacy/plugins/spaces/index.ts

@@ -12,9 +12,7 @@ import { SpacesServiceSetup } from '../../../plugins/spaces/server';
 import { SpacesPluginSetup } from '../../../plugins/spaces/server';
 // @ts-ignore
 import { AuditLogger } from '../../server/lib/audit_logger';
-import mappings from './mappings.json';
 import { wrapError } from './server/lib/errors';
-import { migrateToKibana660 } from './server/lib/migrations';
 // @ts-ignore
 import { watchStatusAndLicenseToInitialize } from '../../server/lib/watch_status_and_license_to_initialize';
 import { initEnterSpaceView } from './server/routes/views';
@@ -39,18 +37,6 @@ export const spaces = (kibana: Record<string, any>) =>
       managementSections: [],
       apps: [],
       hacks: ['plugins/spaces/legacy'],
-      mappings,
-      migrations: {
-        space: {
-          '6.6.0': migrateToKibana660,
-        },
-      },
-      savedObjectSchemas: {
-        space: {
-          isNamespaceAgnostic: true,
-          hidden: true,
-        },
-      },
       home: [],
       injectDefaultVars(server: Server) {
         return {
@@ -100,7 +86,6 @@ export const spaces = (kibana: Record<string, any>) =>
       const { registerLegacyAPI, createDefaultSpace } = spacesPlugin.__legacyCompat;
 
       registerLegacyAPI({
-        savedObjects: server.savedObjects,
         auditLogger: {
           create: (pluginId: string) =>
             new AuditLogger(server, pluginId, server.config(), server.plugins.xpack_main.info),