Set custom color to specific files and folder names

Issue: #160 (closed)

FEATURE TO BE IMPLEMENTED

Add option to highlight a particular folder to a specified color. This would help with easier identification of important/marked files and folders.

• Implement the UI for selecting highlight colors.
• Implement the backend to toggle this feature on/off & save the color string as a metadata.
• Enable rendering of the highlights on the different views.
• Implement Rounded corners for standard view & compact view.
• Example box in properties-dialog.