qml: show "tx fee rate" in TxDetails, like in other guis

electrum/gui/qml/components/TxDetails.qml

@@ -117,6 +117,18 @@ Pane {
                         }
                     }
 
+                    Label {
+                        visible: txdetails.feeRateStr != ""
+                        text: qsTr('Transaction fee rate')
+                        color: Material.accentColor
+                    }
+
+                    Label {
+                        Layout.fillWidth: true
+                        visible: txdetails.feeRateStr != ""
+                        text: txdetails.feeRateStr
+                    }
+
                     Label {
                         Layout.fillWidth: true
                         text: qsTr('Status')

electrum/gui/qml/qetxdetails.py

@@ -37,6 +37,7 @@ class QETxDetails(QObject, QtEventListener):
         self._amount = QEAmount()
         self._lnamount = QEAmount()
         self._fee = QEAmount()
+        self._feerate_str = ''
         self._inputs = []
         self._outputs = []
 
@@ -145,6 +146,10 @@ class QETxDetails(QObject, QtEventListener):
     def fee(self):
         return self._fee
 
+    @pyqtProperty(str, notify=detailsChanged)
+    def feeRateStr(self):
+        return self._feerate_str
+
     @pyqtProperty('QVariantList', notify=detailsChanged)
     def inputs(self):
         return self._inputs
@@ -259,6 +264,12 @@ class QETxDetails(QObject, QtEventListener):
         self._status = txinfo.status
         self._fee.satsInt = txinfo.fee
 
+        self._feerate_str = ""
+        if txinfo.fee is not None:
+            size = self._tx.estimated_size()
+            fee_per_kb = txinfo.fee / size * 1000
+            self._feerate_str = self._wallet.wallet.config.format_fee_rate(fee_per_kb)
+
         self._is_mined = False if not txinfo.tx_mined_status else txinfo.tx_mined_status.height > 0
         if self._is_mined:
             self.update_mined_status(txinfo.tx_mined_status)