Set PerChannelReserveSats rather than TrustedPeersNoReserve

[rolznz]

After a channel is closed with stuck HTLCs, Alby Hub will not try to claim contestable funds since it trusts the LSP. This means we need to actively contact the LSP for a refund.

We can do a middle ground by instead of keeping a list of TrustedPeersNoReserve we can set the PerChannelReserveSats to 0. This should still allow channels to be made with 0 on-chain balance, but if the user does have some on-chain balance, they can spend it to ensure their funds are returned to them. It's not perfect because the user might not have on-chain funds. But it should be a bit better than now.