Disabled output field until the input field is populated to suppress errors that occur when trying to populate the drop down menu (if input string can't be matched this would happen). The error did not break the extension but this way is cleaner.

- Added some checks to detect input MAC
- Refactored some code

- Corrected some formatting issue where all elements didn't fit inside the extensions popup

- Added function to paste copied MAC from clipboard (no longer required to click the box, right click and paste, reducing click count overtime).