Touch command should be sent to all write owners

During state transfer, new owners are only write owners, and they do not receive remote get commands or touch commands.

This means a key can expire too early in a scenario like this:

1. A owns k=v with max-idle=10000, last-access=0
2. state transfer starts, read-owners=A, write-owners=AB
3. A sends to B entry k=v with last-access=0
4. get(k) updates last-access=9000 on A but not on B
5. state transfer ends, read-owners=write-owners=AB
6. rebalance ends, read-owners=write-owners=B
7. get(k) at timestamp 11000 finds k=v has expired and removes it

Touch commands are more like writes than reads, so they should be sent to both read and write-only owners.