Moved URL string to general

[snipe]

This just moves the url translation string that was duplicated in a few places to be in general.

[what-the-diff]

PR Summary

• Refactored URL Labelling Across Files
  The term 'URL' was being defined separately in multiple file locations. It's now moved to a central location in resources/lang/en-US/general.php, leading to a uniform URL label across the platform.
• Optimized Label Text in Manufacturer and Supplier Edits
  The label text for 'URL' in both the manufacturer and supplier edit panels, previously sourced from their respective directories, are now uniformly referenced from general.url, improving code reusability.
• Standardized Checkbox Label Text
  The checkbox label text for URL on the custom report page is now referenced from general.url instead of the previous manufacturer-specific label, ensuring consistency.
• Optimized Column Header in Supplier Views
  The column header for URL in supplier view tables was labeled using a supplier-specific definition. It now uses the general label leading to a more consistent user experience.

By these changes, future updates to this label will be easier to implement and provide a uniform experience across different sections of the platform.