[APM] Migrate /test/apm_api_integration/tests/storage_explorer to be deployment-agnostic API tests

[rmyz]

API	ESS	Serverless	Test files
GET /internal/apm/storage_explorer/get_services	✅	❌	ESS: ./test/apm_api_integration/tests/storage_explorer/get_services.spec.ts
GET /internal/apm/services/{serviceName}/storage_details	✅	❌	ESS: ./test/apm_api_integration/tests/storage_explorer/storage_details.spec.ts
GET /internal/apm/storage_explorer	✅	❌	ESS: ./test/apm_api_integration/tests/storage_explorer/storage_explorer.spec.ts
GET /internal/apm/storage_explorer/privileges	✅	❌	ESS: ./test/apm_api_integration/tests/storage_explorer/storage_explorer_privileges.spec.ts
GET /internal/apm/storage_explorer_summary_stats	✅	❌	ESS: ./test/apm_api_integration/tests/storage_explorer/storage_explorer_summary_stats.spec.ts
GET /internal/apm/storage_chart	✅	❌	ESS: ./test/apm_api_integration/tests/storage_explorer/storage_explorer_timeseries_chart.spec.ts

[rmyz]

Closing this one as storage_explorer is completely disabled for serverless.

CC @crespocarlos