Auto-Close on update_fee delay

[TheBlueMatt]

If we intend to update the channel fee on an outbound channel (or if we just think our channel fee is really far off on an inbound channel) and its been a while since we've managed to connect with them (or they're not ack'ing our update_fee), we should probably force-close the channel out of fear for our inability to get the channel close confirmed. This does not apply to anchor.

[ariard]

Marking this 0.0.101 as otherwise it's a significant risk of stale feerate in case of emergency unilateral close.

Note, I think we should only proceed to the auto-close in case of pending HTLC to solve. Otherwise should we really care about empty commitment transaction with staled feerate ? As long as it's committed with a mempool min fee high-enough.

[TheBlueMatt]

Moved back to 0.1 as with #1056 as we should block prod for this, but not user testing.