[Search] enable enterpriseSearch plugin in Security (#216234)

## Summary

This PR enables Enterprise Search in 8.x for Security spaces so that
connectors and crawlers are available.
### Closes  https://github.com/elastic/search-team/issues/9281

<img width="1899" alt="Screenshot 2025-03-27 at 4 27 02 PM"
src="https://github.com/user-attachments/assets/d3ab37f3-c6b4-4bdb-8650-0b71feffe4bc"
/>

<img width="1903" alt="Screenshot 2025-03-27 at 4 27 09 PM"
src="https://github.com/user-attachments/assets/eb0043c6-7781-4024-bc36-7f6cb11d2269"
/>

### Checklist

Check the PR satisfies following conditions. 

Reviewers should verify this PR satisfies this list as well.

- [ ] Any text added follows [EUI's writing
guidelines](https://elastic.github.io/eui/#/guidelines/writing), uses
sentence case text and includes [i18n
support](https://github.com/elastic/kibana/blob/main/src/platform/packages/shared/kbn-i18n/README.md)
- [ ]
[Documentation](https://www.elastic.co/guide/en/kibana/master/development-documentation.html)
was added for features that require explanation or tutorials
- [x] [Unit or functional
tests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)
were updated or added to match the most common scenarios
- [ ] If a plugin configuration key changed, check if it needs to be
allowlisted in the cloud and added to the [docker
list](https://github.com/elastic/kibana/blob/main/src/dev/build/tasks/os_packages/docker_generator/resources/base/bin/kibana-docker)
- [ ] This was checked for breaking HTTP API changes, and any breaking
changes have been approved by the breaking-change committee. The
`release_note:breaking` label should be applied in these situations.
- [ ] [Flaky Test
Runner](https://ci-stats.kibana.dev/trigger_flaky_test_runner/1) was
used on any tests changed
- [ ] The PR description includes the appropriate Release Notes section,
and the correct `release_note:*` label is applied per the
[guidelines](https://www.elastic.co/guide/en/kibana/master/contributing.html#kibana-release-notes-process)

### Identify risks

Does this PR introduce any risks? For example, consider risks like hard
to test bugs, performance regression, potential of data loss.

Describe the risk, its severity, and mitigation for each identified
risk. Invite stakeholders and evaluate how to proceed before merging.

- [ ] [See some risk
examples](https://github.com/elastic/kibana/blob/main/RISK_MATRIX.mdx)
- [ ] ...

---------

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

x-pack/platform/plugins/shared/spaces/server/capabilities/capabilities_switcher.test.ts

@@ -407,8 +407,8 @@ describe('capabilitiesSwitcher', () => {
       {
         space.solution = 'security';
 
-        // It should disable enterpriseSearch and observability features
-        // which correspond to feature_1 and feature_2
+        // It should disable observability features
+        // which corresponds to feature_2
         const result = await switcher(request, capabilities, false);
 
         const expectedCapabilities = buildCapabilities();
@@ -417,8 +417,6 @@ describe('capabilitiesSwitcher', () => {
         expectedCapabilities.catalogue.feature2Entry = false;
         expectedCapabilities.navLinks.feature3 = false;
         expectedCapabilities.management.kibana.somethingElse = false;
-        expectedCapabilities.feature_1.bar = false;
-        expectedCapabilities.feature_1.foo = false;
         expectedCapabilities.feature_2.bar = false;
         expectedCapabilities.feature_2.foo = false;
 

x-pack/platform/plugins/shared/spaces/server/lib/utils/space_solution_disabled_features.test.ts

@@ -73,7 +73,7 @@ describe('#withSpaceSolutionDisabledFeatures', () => {
   });
 
   describe('when the space solution is "security"', () => {
-    test('it removes the "observability" and "enterpriseSearch" features', () => {
+    test('it removes the "observability" feature', () => {
       const spaceDisabledFeatures: string[] = ['baz'];
       const spaceSolution = 'security';
 
@@ -83,7 +83,7 @@ describe('#withSpaceSolutionDisabledFeatures', () => {
         spaceSolution
       );
 
-      expect(result).toEqual(['feature1', 'feature2']); // "baz" from the spaceDisabledFeatures should not be removed
+      expect(result).toEqual(['feature1']); // "baz" from the spaceDisabledFeatures should not be removed
     });
   });
 });

x-pack/platform/plugins/shared/spaces/server/lib/utils/space_solution_disabled_features.ts

@@ -67,7 +67,6 @@ export function withSpaceSolutionDisabledFeatures(
   } else if (spaceSolution === 'security') {
     disabledFeatureKeysFromSolution = getFeatureIdsForCategories(features, [
       'observability',
-      'enterpriseSearch',
     ]).filter((featureId) => !enabledFeaturesPerSolution.security.includes(featureId));
   }