Redesign add-notes dialog box

Fixes #88 (closed)

• Add a minimum size to the dialog box (300 X 200) (400 X 300).
• Fixes "expansion of dialog box" with the length of the text-note. Now, it wraps text according to GTK_WRAP_CHAR.
• Add a vertical scrollable bar to the window if text-note exceeds the height of the dialog window.
• Convert the existing dialog into an Action Dialog.