qml: Give user feedback after bumping the fee.

This is better than nothing, but not ideal. This window should
have a general purpose 'userinfo' field, like InvoiceDialog,
that would also display 'Broadcasting...' while the tx is being
broadcast.

Note that in order to bump the fee again, the user will have to
leave this window and open it again.

electrum/gui/qml/components/TxDetails.qml

@@ -139,6 +139,7 @@ Pane {
                                 ? 1
                                 : 2
                             Label {
+                                id: bumpfeeinfo
                                 Layout.fillWidth: true
                                 text: qsTr('This transaction is still unconfirmed.') + '\n' + (txdetails.canCancel
                                     ? qsTr('You can increase fees to speed up the transaction, or cancel this transaction')
@@ -449,6 +450,10 @@ Pane {
             var dialog = app.messageDialog.createObject(app, { text: message })
             dialog.open()
         }
+        function onBroadcastSucceeded() {
+            bumpfeeinfo.text = qsTr('Transaction was broadcast successfully')
+            actionButtonsLayout.visible = false
+        }
     }
 
     Component {
@@ -464,7 +469,6 @@ Pane {
                 root.rawtx = rbffeebumper.getNewTx()
                 if (txdetails.wallet.canSignWithoutCosigner) {
                     txdetails.sign_and_broadcast()
-                    // close txdetails?
                 } else {
                     var dialog = app.messageDialog.createObject(app, {
                         text: qsTr('Transaction fee updated.') + '\n\n' + qsTr('You still need to sign and broadcast this transaction.')
@@ -491,7 +495,6 @@ Pane {
                 root.rawtx = cpfpfeebumper.getNewTx()
                 if (txdetails.wallet.canSignWithoutCosigner) {
                     txdetails.sign_and_broadcast()
-                    // close txdetails?
                 } else {
                     var dialog = app.messageDialog.createObject(app, {
                         text: qsTr('CPFP fee bump transaction created.') + '\n\n' + qsTr('You still need to sign and broadcast this transaction.')
@@ -517,7 +520,6 @@ Pane {
                 root.rawtx = txcanceller.getNewTx()
                 if (txdetails.wallet.canSignWithoutCosigner) {
                     txdetails.sign_and_broadcast()
-                    // close txdetails?
                 } else {
                     var dialog = app.messageDialog.createObject(app, {
                         text: qsTr('Cancel transaction created.') + '\n\n' + qsTr('You still need to sign and broadcast this transaction.')