[Entity Manager] Extract the entity manager out of Observability solution (#190304)

## Summary

Moving the Entity Manager out of Observability and into a Kibana plugin
as per [this
ticket](https://github.com/elastic/security-team/issues/10156)

---------

Co-authored-by: kibanamachine <42973632+kibanamachine@users.noreply.github.com>

.github/CODEOWNERS

@@ -402,7 +402,7 @@ x-pack/plugins/enterprise_search @elastic/search-kibana
 x-pack/plugins/observability_solution/entities_data_access @elastic/obs-entities
 x-pack/packages/kbn-entities-schema @elastic/obs-entities
 x-pack/test/api_integration/apis/entity_manager/fixture_plugin @elastic/obs-entities
-x-pack/plugins/observability_solution/entity_manager @elastic/obs-entities
+x-pack/plugins/entity_manager @elastic/obs-entities
 examples/error_boundary @elastic/appex-sharedux
 packages/kbn-es @elastic/kibana-operations
 packages/kbn-es-archiver @elastic/kibana-operations @elastic/appex-qa

docs/developer/plugin-list.asciidoc

@@ -570,7 +570,7 @@ security and spaces filtering.
 |Exposes services to access entities data.
 
 
-|{kib-repo}blob/{branch}/x-pack/plugins/observability_solution/entity_manager/README.md[entityManager]
+|{kib-repo}blob/{branch}/x-pack/plugins/entity_manager/README.md[entityManager]
 |This plugin provides access to observed entity data, such as information about hosts, pods, containers, services, and more.
 
 

package.json

@@ -464,7 +464,7 @@
     "@kbn/entities-data-access-plugin": "link:x-pack/plugins/observability_solution/entities_data_access",
     "@kbn/entities-schema": "link:x-pack/packages/kbn-entities-schema",
     "@kbn/entity-manager-fixture-plugin": "link:x-pack/test/api_integration/apis/entity_manager/fixture_plugin",
-    "@kbn/entityManager-plugin": "link:x-pack/plugins/observability_solution/entity_manager",
+    "@kbn/entityManager-plugin": "link:x-pack/plugins/entity_manager",
     "@kbn/error-boundary-example-plugin": "link:examples/error_boundary",
     "@kbn/es-errors": "link:packages/kbn-es-errors",
     "@kbn/es-query": "link:packages/kbn-es-query",

tsconfig.base.json

@@ -798,8 +798,8 @@
       "@kbn/entities-schema/*": ["x-pack/packages/kbn-entities-schema/*"],
       "@kbn/entity-manager-fixture-plugin": ["x-pack/test/api_integration/apis/entity_manager/fixture_plugin"],
       "@kbn/entity-manager-fixture-plugin/*": ["x-pack/test/api_integration/apis/entity_manager/fixture_plugin/*"],
-      "@kbn/entityManager-plugin": ["x-pack/plugins/observability_solution/entity_manager"],
-      "@kbn/entityManager-plugin/*": ["x-pack/plugins/observability_solution/entity_manager/*"],
+      "@kbn/entityManager-plugin": ["x-pack/plugins/entity_manager"],
+      "@kbn/entityManager-plugin/*": ["x-pack/plugins/entity_manager/*"],
       "@kbn/error-boundary-example-plugin": ["examples/error_boundary"],
       "@kbn/error-boundary-example-plugin/*": ["examples/error_boundary/*"],
       "@kbn/es": ["packages/kbn-es"],

x-pack/plugins/entity_manager/jest.config.js

@@ -7,12 +7,11 @@
 
 module.exports = {
   preset: '@kbn/test',
-  rootDir: '../../../..',
-  roots: ['<rootDir>/x-pack/plugins/observability_solution/entity_manager'],
-  coverageDirectory:
-    '<rootDir>/target/kibana-coverage/jest/x-pack/plugins/observability_solution/entity_manager',
+  rootDir: '../../..',
+  roots: ['<rootDir>/x-pack/plugins/entity_manager'],
+  coverageDirectory: '<rootDir>/target/kibana-coverage/jest/x-pack/plugins/entity_manager',
   coverageReporters: ['text', 'html'],
   collectCoverageFrom: [
-    '<rootDir>/x-pack/plugins/observability_solution/entity_manager/{common,public,server}/**/*.{js,ts,tsx}',
+    '<rootDir>/x-pack/plugins/entity_manager/{common,public,server}/**/*.{js,ts,tsx}',
   ],
 };