Always open the find/replace dialog with Ctrl+H and option in context menu

The shortcut is constrained to the Widget context so it does not conflict
with other SqlTextEdit widgets in the application. Now all SqlTextEdit
widgets are able of opening the dialog with the same shortcut and behave
in the same way (do not block the parent window).

The find/replace dialog can now be discovered by the user in the context
menu at the SqlTextEdit widgets.

src/sqltextedit.h

@@ -3,6 +3,7 @@
 
 #include "Qsci/qsciscintilla.h"
 
+class FindReplaceDialog;
 class SqlUiLexer;
 
 /**
@@ -26,6 +27,7 @@ public slots:
     void reloadSettings();
     void clearErrorIndicators();
     void setErrorIndicator(int fromRow, int fromIndex, int toRow, int toIndex);
+    void openFindReplaceDialog();
 
 protected:
     void dropEvent(QDropEvent* e);
@@ -35,10 +37,11 @@ private:
 
     int errorIndicatorNumber;
     bool showErrorIndicators;
+    FindReplaceDialog* findReplaceDialog;
 
 private slots:
     void updateLineNumberAreaWidth();
-    void openFindReplaceDialog();
+    void showContextMenu(const QPoint &pos);
 };
 
 #endif