[Serverless Search] Disable Grok debugger & Painless Lab (#165772)

## Summary

Updated the grok debugger and painless lab plugins to handle the
`enabled` config flag so they can easily be disabled for serverless
search.

### Screenshots
Before:

![image](7552954b-11f1-4c6f-9007-148a8c765c3f)

After:
<img width="1914" alt="image"
src="ad48ba1b-0f1d-4da3-aeac-4868781f6832">

config/serverless.es.yml

@@ -31,3 +31,7 @@ xpack.actions.enabledActionTypes: ['.email', '.index', '.slack', '.jira', '.webh
 
 # Customize empty page state for analytics apps
 no_data_page.analyticsNoDataPageFlavor: 'serverless_search'
+
+# Disable Dev tools
+xpack.grokdebugger.enabled: false
+xpack.painless_lab.enabled: false

x-pack/plugins/grokdebugger/server/index.js

@@ -5,8 +5,10 @@
  * 2.0.
  */
 
-import { Plugin } from './plugin';
+import { Plugin, config } from './plugin';
 
-export function plugin(initializerContext) {
-  return new Plugin(initializerContext);
+export function plugin() {
+  return new Plugin();
 }
+
+export { config };

x-pack/plugins/grokdebugger/server/plugin.js

@@ -5,13 +5,15 @@
  * 2.0.
  */
 
-import { schema } from '@kbn/config-schema';
+import { offeringBasedSchema, schema } from '@kbn/config-schema';
 import { KibanaFramework } from './lib/kibana_framework';
 import { registerGrokdebuggerRoutes } from './routes/api/grokdebugger';
 
 export const config = {
   schema: schema.object({
-    enabled: schema.boolean({ defaultValue: true }),
+    enabled: offeringBasedSchema({
+      serverless: schema.boolean({ defaultValue: true }),
+    }),
   }),
 };
 

x-pack/plugins/painless_lab/server/index.ts

@@ -5,9 +5,21 @@
  * 2.0.
  */
 
-import { PluginInitializerContext } from '@kbn/core/server';
+import { offeringBasedSchema, schema, TypeOf } from '@kbn/config-schema';
+import { PluginInitializerContext, PluginConfigDescriptor } from '@kbn/core/server';
 import { PainlessLabServerPlugin } from './plugin';
 
+export const configSchema = schema.object({
+  enabled: offeringBasedSchema({
+    serverless: schema.boolean({ defaultValue: true }),
+  }),
+});
+export type ConfigType = TypeOf<typeof configSchema>;
+
+export const config: PluginConfigDescriptor<ConfigType> = {
+  schema: configSchema,
+};
+
 export const plugin = (ctx: PluginInitializerContext) => {
   return new PainlessLabServerPlugin(ctx);
 };

x-pack/plugins/serverless_search/kibana.jsonc

@@ -18,10 +18,8 @@
       "dashboard",
       "devTools",
       "discover",
-      "grokdebugger",
       "management",
       "ml",
-      "painlessLab",
       "searchprofiler",
       "security",
       "serverless",