Create widget for Layers for the project window

[StephenNneji]

This should be a widget for the Layers table. The widget should be placed in the Layers tab and contain the layers table as shown below.

• The layers tab should only be visible for standard layers project
• In the edit mode the table should have the delete buttons on the left and add button below
• If the absorption in the project class is true, the tables should expand to show the SLD real and SLD imaginary tables