Implement dialogs to edit valueColors for different plot types

#59 (closed)

• Implement super class EditValueColorDialog for editing valueColors dialog for different plot_types
• Implement dialog UpDownDialog to edit valueColors for upDownDots that inherit from EditValueColorDialog.
• Implement dialog LineDotDialog to edit valueColors for linesDots that inherit from EditValueColorDialog.
• Implement dialog TriColorLinesDialog to edit valueColors for triColorLines that inherit from EditValueColorDialog.