[AI-FSSDK] [FSSDK-12670] Block ODP identify events with single identifier

[jaeopt]

Summary

Block ODP identify events when only a single valid identifier is provided. Identify events exist to link multiple user identifiers together; sending them with a single identifier provides no value and wastes network calls.

Jira: FSSDK-12670

Changes

pkg/odp/event/event_manager.go

• Changed IdentifyUser signature from (apiKey, apiHost, userID string) to (apiKey, apiHost string, identifiers map[string]string)
• Added filtering of empty identifier values before count check
• Added guard: requires 2+ valid identifiers to dispatch identify event
• Added debug log message when skipping: "ODP identify event is not dispatched (only one identifier provided)."

pkg/odp/odp_manager.go

• Updated IdentifyUser to build identifiers map from userID and pass to event manager
• Added identifyUserIdentifiers helper function
• Updated event.Manager interface to match new signature

Tests

• Updated existing identify tests to use new map-based signature
• Added TestIdentifyUserSkippedWithSingleIdentifier - verifies single identifier blocked
• Added TestIdentifyUserSkippedWithEmptyValues - verifies empty values filtered out
• Updated async behavior test to use two identifiers

Notes

• Go SDK is server-side only (no VUID), so IdentifyUser will always have a single fs_user_id identifier and identify events will be correctly skipped
• The OdpManager.Manager public interface (IdentifyUser(userID string)) is unchanged for backward compatibility
• The signature change is internal to the event.Manager interface