Merge pull request #6770 from Roasbeef/co-op-close-with-more-spec-innit

lnwallet/chancloser: remove the commit fee clamp, introduce max fee

lnrpc/lightning.proto

@@ -1910,6 +1910,11 @@ message CloseChannelRequest {
     // A manual fee rate set in sat/vbyte that should be used when crafting the
     // closure transaction.
     uint64 sat_per_vbyte = 6;
+
+    // The maximum fee rate the closer is willing to pay.
+    //
+    // NOTE: This field is only respected if we're the initiator of the channel.
+    uint64 max_fee_per_vbyte = 7;
 }
 
 message CloseStatusUpdate {