fix: OnEvent fixes

[Nerivec]

• Call onEvent stop when device leaves (ensures cleared timers, no use of stale refs)
• Pass proper data to onEvent
• Fix deviceExposesChanged using Zh.Device instead of Device (used by HA discovery, KeyValue typing was hiding it)
  • looks like a test for HA extension should be added to cover this
• Use Map for Device/Group lookups
• Fix resolveGroup typing possibly undefined
• Rewrite OnEvent tests

Rest is mostly pre-emptive strikes for biome move.