## Summary

Since Scout will soon support `api` testing, we need to re-org scout
test directory so that both ui and api playwright configs can be
discovered and executed independently. Proposed structure:

```
- plugin
 |- test
   |- scout
     |- common // fixtures/constants to share across both 'ui' and 'api' tests
     |- ui
        |-tests
        |-parallel_tests
        |-playwright.config.ts
        |-playwright.parallel.config.ts
     |- api
        |-tests
        |-parallel_tests
        |-playwright.config.ts
        |-playwright.parallel.config.ts
```

This PR updates all the existing scout directories

---------

Co-authored-by: kibanamachine <42973632+kibanamachine@users.noreply.github.com>
(cherry picked from commit 5d49f1b)

# Conflicts:
#	.github/CODEOWNERS
#	src/platform/packages/shared/kbn-scout/src/config/discovery/search_configs.ts
#	x-pack/platform/packages/private/ml/kibana_theme/tsconfig.json
#	x-pack/solutions/observability/plugins/apm/test/scout/README.md
#	x-pack/solutions/observability/plugins/apm/test/scout/ui/fixtures/constants.ts
#	x-pack/solutions/observability/plugins/apm/test/scout/ui/fixtures/index.ts
#	x-pack/solutions/observability/plugins/apm/test/scout/ui/fixtures/page_objects/service_inventory.ts
#	x-pack/solutions/observability/plugins/apm/test/scout/ui/fixtures/page_objects/service_map.ts
#	x-pack/solutions/observability/plugins/apm/test/scout/ui/fixtures/synthtrace/opbeans.ts
#	x-pack/solutions/observability/plugins/apm/test/scout/ui/parallel.playwright.config.ts
#	x-pack/solutions/observability/plugins/apm/test/scout/ui/parallel_tests/global_setup.ts
#	x-pack/solutions/observability/plugins/apm/test/scout/ui/parallel_tests/service_inventory/service_inventory.spec.ts
#	x-pack/solutions/observability/plugins/apm/test/scout/ui/parallel_tests/sevice_map/service_map.spec.ts
#	x-pack/solutions/observability/plugins/apm/test/scout/ui/tsconfig.json
#	x-pack/solutions/observability/plugins/apm/ui_tests/fixtures/constants.ts
#	x-pack/solutions/observability/plugins/apm/ui_tests/parallel.playwright.config.ts
#	x-pack/solutions/observability/plugins/apm/ui_tests/tsconfig.json
#	x-pack/solutions/observability/plugins/observability/test/scout/README.md
#	x-pack/solutions/observability/plugins/observability/test/scout/ui/fixtures/generators.ts
#	x-pack/solutions/observability/plugins/observability/test/scout/ui/playwright.config.ts
#	x-pack/solutions/observability/plugins/observability/test/scout/ui/tests/landing.spec.ts
#	x-pack/solutions/observability/plugins/observability/tsconfig.json
#	x-pack/solutions/observability/plugins/observability/ui_tests/playwright.config.ts
#	x-pack/solutions/observability/plugins/observability_onboarding/README.md
#	x-pack/solutions/search/plugins/enterprise_search/public/applications/app_search/components/documents/constants.ts
#	x-pack/solutions/search/plugins/search_indices/public/components/index_documents/constants.ts
#	x-pack/test/kubernetes_security/basic/config.ts