fee and lock_height maintained in kernel features variants (#2859)

* fee and lock_height now maintained in kernel features enum variants

* sum fees via explicit enum variants

* cleanup semantics around with_fee and with_lock_height for tx builders

* document the kernel feature variants

* serialize kernel features correctly for api json

* cleanup

* commit

* bump to unstick azure

api/src/types.rs

@@ -17,6 +17,7 @@ use std::sync::Arc;
 use crate::chain;
 use crate::core::core::hash::Hashed;
 use crate::core::core::merkle_proof::MerkleProof;
+use crate::core::core::KernelFeatures;
 use crate::core::{core, ser};
 use crate::p2p;
 use crate::util;
@@ -488,10 +489,16 @@ pub struct TxKernelPrintable {
 
 impl TxKernelPrintable {
 	pub fn from_txkernel(k: &core::TxKernel) -> TxKernelPrintable {
+		let features = k.features.as_string();
+		let (fee, lock_height) = match k.features {
+			KernelFeatures::Plain { fee } => (fee, 0),
+			KernelFeatures::Coinbase => (0, 0),
+			KernelFeatures::HeightLocked { fee, lock_height } => (fee, lock_height),
+		};
 		TxKernelPrintable {
-			features: format!("{:?}", k.features),
-			fee: k.fee,
-			lock_height: k.lock_height,
+			features,
+			fee,
+			lock_height,
 			excess: util::to_hex(k.excess.0.to_vec()),
 			excess_sig: util::to_hex(k.excess_sig.to_raw_data().to_vec()),
 		}