ctkDICOMobjectListWidget enhancements

ctkDICOMobjectListWidget enhancements
1.file spin box added
2. file slider single step set to 1
3. changed the order of columns in dicom table to: Tag, Attribute, value, VR, Length
4. Double-click on tag table item would open the browser and search the tag in dicomlookup.com
5. Added copy file path to the clipboard and polished UI.