Add valdiation of REST extension properties for virtual procedures

The recognition of REST extension properties keys off of both REST METHOD and REST URI properties either both being present or both null.

Workspace Validation: Create a RestPropertiesValidationRule to create a problem marker if this is not the case

Procedure Wizard validation:

• Add CHARSET and HEADERS property Widgets to ViewProcedureEditorPanel
• Add charset and header instance variables to RelationalViewProcedure object (include getter/setter methods)
• Add validation to ViewProcedureEditorPanel to verify the same.

Thinking in both instances we should default the severity to WARNING and not error.