Allow renaming SQL tabs by double clicking them

See issue #1186.

src/MainWindow.cpp

@@ -2626,3 +2626,15 @@ void MainWindow::requestCollation(const QString& name, int eTextRep)
     if(reply == QMessageBox::Yes)
         sqlite3_create_collation(db._db, name.toUtf8(), eTextRep, nullptr, collCompare);
 }
+
+void MainWindow::renameSqlTab(int index)
+{
+    QString new_name = QInputDialog::getText(this,
+                                             qApp->applicationName(),
+                                             tr("Set a new name for the SQL tab. Use the '&' character to allow using the following character as a keyboard shortcut."),
+                                             QLineEdit::EchoMode::Normal,
+                                             ui->tabSqlAreas->tabText(index));
+
+    if(!new_name.isNull())      // Don't do anything if the Cancel button was clicked
+        ui->tabSqlAreas->setTabText(index, new_name);
+}

src/MainWindow.h

@@ -285,6 +285,7 @@ private slots:
     void hideColumns(int column = -1, bool hide = true);
     void on_actionShowAllColumns_triggered();
     void requestCollation(const QString& name, int eTextRep);
+    void renameSqlTab(int index);
 };
 
 #endif

src/MainWindow.ui

@@ -2937,6 +2937,22 @@
     </hint>
    </hints>
   </connection>
+  <connection>
+   <sender>tabSqlAreas</sender>
+   <signal>tabBarDoubleClicked(int)</signal>
+   <receiver>MainWindow</receiver>
+   <slot>renameSqlTab(int)</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>330</x>
+     <y>372</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>518</x>
+     <y>314</y>
+    </hint>
+   </hints>
+  </connection>
  </connections>
  <slots>
   <slot>fileOpen()</slot>
@@ -3005,5 +3021,6 @@
   <slot>saveSqlResultsAsView()</slot>
   <slot>changeSqlTab(int)</slot>
   <slot>hideColumns()</slot>
+  <slot>renameSqlTab(int)</slot>
  </slots>
 </ui>