Fix: return list from translate_event_code to dispatch all matching listeners

[MicheleMercuri]

Summary

Fixes #560 — regression from #557 where CrossLineDetection sensors stopped firing when SmartMotionHuman/SmartMotionVehicle listeners also existed.

Root cause: translate_event_code() returned a single event code string. When both a CrossLine and a SmartMotion listener were registered, the CrossLine event was exclusively translated to SmartMotion — the original CrossLineDetection sensor never fired.

Fix: translate_event_code() now returns a list[str] of event codes, and both callers (on_receive_vto_event, on_receive) iterate over the list to dispatch all matching listeners.

Behavior matrix

User config	CrossLine + ObjectType=Human	Result
Only CrossLine subscribed	[CrossLineDetection]	works (unchanged)
Only SmartMotion subscribed	[SmartMotionHuman]	works (unchanged)
Both subscribed	[CrossLineDetection, SmartMotionHuman]	both fire (was broken)
Neither subscribed	[SmartMotionHuman] fallback	works (unchanged)

Changes (3 touch points in __init__.py)

1. translate_event_code() — returns list[str] instead of str. Builds a list: always includes original CrossLine/CrossRegion if its listener exists, then appends SmartMotion* if that listener also exists.
2. on_receive_vto_event() — codes = ... + for code in codes: loop around the existing handler body.
3. on_receive() — event_names = ... + for event_name in event_names: loop around the existing handler body.

Test plan

• Verified on 4 Dahua cameras with IVS CrossLineDetection + SmartMotionHuman both enabled — both binary_sensor.*_crosslinedetection and binary_sensor.*_smart_motion_human fire on the same event
• Verified CrossLineDetection-only setup (no SmartMotion entities) still works
• Verified SmartMotionHuman-only setup (no CrossLine entities) still works
• Verified doorbell (BackKeyLight → DoorbellPressed) still works (returns ["DoorbellPressed"])
• Verified VTO events (AccessControl, DoorStatus Pulse) still work

[rroller]

Thanks!