qt: Replace disambiguation strings with translator comments

Translator comments is the right way to pass context to translators.

src/qt/addressbookpage.cpp

@@ -281,7 +281,9 @@ void AddressBookPage::on_exportButton_clicked()
     // CSV is currently the only supported format
     QString filename = GUIUtil::getSaveFileName(this,
         tr("Export Address List"), QString(),
-        tr("Comma separated file", "Name of CSV file format") + QLatin1String(" (*.csv)"), nullptr);
+        /*: Expanded name of the CSV file format.
+            See https://en.wikipedia.org/wiki/Comma-separated_values */
+        tr("Comma separated file") + QLatin1String(" (*.csv)"), nullptr);
 
     if (filename.isNull())
         return;
@@ -295,8 +297,9 @@ void AddressBookPage::on_exportButton_clicked()
 
     if(!writer.write()) {
         QMessageBox::critical(this, tr("Exporting Failed"),
-            //: %1 is a name of the file (e.g., "addrbook.csv") that the bitcoin addresses were exported to.
-            tr("There was an error trying to save the address list to %1. Please try again.", "An error message.").arg(filename));
+            /*: An error message. %1 is a stand-in argument for the name
+                of the file we attempted to save to. */
+            tr("There was an error trying to save the address list to %1. Please try again.").arg(filename));
     }
 }
 

src/qt/intro.cpp

@@ -385,7 +385,9 @@ void Intro::UpdatePruneLabels(bool prune_checked)
     static constexpr uint64_t nPowTargetSpacing = 10 * 60;  // from chainparams, which we don't have at this stage
     static constexpr uint32_t expected_block_data_size = 2250000;  // includes undo data
     const uint64_t expected_backup_days = m_prune_target_gb * 1e9 / (uint64_t(expected_block_data_size) * 86400 / nPowTargetSpacing);
-    ui->lblPruneSuffix->setText(tr("(sufficient to restore backups %n day(s) old)", "block chain pruning", expected_backup_days));
+    ui->lblPruneSuffix->setText(
+        //: Explanatory text on the capability of the current prune target.
+        tr("(sufficient to restore backups %n day(s) old)", "", expected_backup_days));
     ui->sizeWarningLabel->setText(
         tr("%1 will download and store a copy of the Bitcoin block chain.").arg(PACKAGE_NAME) + " " +
         storageRequiresMsg.arg(m_required_space_gb) + " " +

src/qt/psbtoperationsdialog.cpp

@@ -141,7 +141,8 @@ void PSBTOperationsDialog::saveTransaction() {
     filename_suggestion.append(".psbt");
     QString filename = GUIUtil::getSaveFileName(this,
         tr("Save Transaction Data"), filename_suggestion,
-        tr("Partially Signed Transaction (Binary)", "Name of binary PSBT file format") + QLatin1String(" (*.psbt)"), &selected_filter);
+        //: Expanded name of the binary PSBT file format. See: BIP 174.
+        tr("Partially Signed Transaction (Binary)") + QLatin1String(" (*.psbt)"), &selected_filter);
     if (filename.isEmpty()) {
         return;
     }

src/qt/qrimagewidget.cpp

@@ -118,7 +118,9 @@ void QRImageWidget::saveImage()
         return;
     QString fn = GUIUtil::getSaveFileName(
         this, tr("Save QR Code"), QString(),
-        tr("PNG Image", "Name of PNG file format") + QLatin1String(" (*.png)"), nullptr);
+        /*: Expanded name of the PNG file format.
+            See https://en.wikipedia.org/wiki/Portable_Network_Graphics */
+        tr("PNG Image") + QLatin1String(" (*.png)"), nullptr);
     if (!fn.isEmpty())
     {
         exportImage().save(fn);

src/qt/sendcoinsdialog.cpp

@@ -432,7 +432,8 @@ void SendCoinsDialog::sendButtonClicked([[maybe_unused]] bool checked)
             fileNameSuggestion.append(".psbt");
             QString filename = GUIUtil::getSaveFileName(this,
                 tr("Save Transaction Data"), fileNameSuggestion,
-                tr("Partially Signed Transaction (Binary)", "Name of binary PSBT file format") + QLatin1String(" (*.psbt)"), &selectedFilter);
+                //: Expanded name of the binary PSBT file format. See: BIP 174.
+                tr("Partially Signed Transaction (Binary)") + QLatin1String(" (*.psbt)"), &selectedFilter);
             if (filename.isEmpty()) {
                 return;
             }

src/qt/transactionview.cpp

@@ -336,7 +336,9 @@ void TransactionView::exportClicked()
     // CSV is currently the only supported format
     QString filename = GUIUtil::getSaveFileName(this,
         tr("Export Transaction History"), QString(),
-        tr("Comma separated file", "Name of CSV file format") + QLatin1String(" (*.csv)"), nullptr);
+        /*: Expanded name of the CSV file format.
+            See https://en.wikipedia.org/wiki/Comma-separated_values */
+        tr("Comma separated file") + QLatin1String(" (*.csv)"), nullptr);
 
     if (filename.isNull())
         return;

src/qt/walletview.cpp

@@ -273,7 +273,8 @@ void WalletView::backupWallet()
 {
     QString filename = GUIUtil::getSaveFileName(this,
         tr("Backup Wallet"), QString(),
-        tr("Wallet Data", "Name of wallet data file format") + QLatin1String(" (*.dat)"), nullptr);
+        //: Name of the wallet data file format.
+        tr("Wallet Data") + QLatin1String(" (*.dat)"), nullptr);
 
     if (filename.isEmpty())
         return;