[ML] Transforms: Migrate client plugin to NP. (#59443) (#59568)

Migrates the client side plugin of transforms to NP.
- Gets rid of the last parts of the shim (http, documentation links)
- Moves the plugin from x-pack/legacy/plugins/transform/public to x-pack/plugins/transform
- Creates a custom mock for appDependencies based on NP services
- Fixes jest tests to get rid of all act() related warnings

x-pack/.i18nrc.json

@@ -39,7 +39,7 @@
     "xpack.snapshotRestore": "plugins/snapshot_restore",
     "xpack.spaces": ["legacy/plugins/spaces", "plugins/spaces"],
     "xpack.taskManager": "legacy/plugins/task_manager",
-    "xpack.transform": ["legacy/plugins/transform", "plugins/transform"],
+    "xpack.transform": "plugins/transform",
     "xpack.triggersActionsUI": "plugins/triggers_actions_ui",
     "xpack.upgradeAssistant": "plugins/upgrade_assistant",
     "xpack.uptime": "legacy/plugins/uptime",

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

@@ -4,19 +4,9 @@
  * you may not use this file except in compliance with the Elastic License.
  */
 
-import { resolve } from 'path';
-
-import { PLUGIN } from './common/constants';
-
 export function transform(kibana: any) {
   return new kibana.Plugin({
-    id: PLUGIN.ID,
+    id: 'transform',
     configPrefix: 'xpack.transform',
-    publicDir: resolve(__dirname, 'public'),
-    require: ['kibana', 'elasticsearch', 'xpack_main'],
-    uiExports: {
-      styleSheetPaths: resolve(__dirname, 'public/app/index.scss'),
-      managementSections: ['plugins/transform'],
-    },
   });
 }