test: add change-server integration tests for ripple, tezos, tron

Verify contract conformance with edge-core-js PR #718:
- usesChangeServer flag set on currencyInfo
- onSubscribeAddresses called on startEngine with wallet address
- syncNetwork exists and returns positive interval
- syncNetwork handles initial sync (subscribeParam == null)
- syncNetwork handles address wakeup (needsSync = true)
- syncNetwork handles caught-up state (needsSync = false)
- Polling loops disabled when usesChangeServer is true
- subscribedAddresses restored from core with checkpoints
- Tron: checkTokenBalances available for syncNetwork
- Tron: fee update loop always active (matches Ethereum pattern)

35 new tests, all passing.

Author: samholmes