Dynamically iterate through the skin listing to build skins

[uberbrady]

I was reading through our webpack file and was getting annoyed at all the horizontal space that was getting eaten up by building skins. So I made it so that it just does a directory listing, then builds each skin that it finds.

Also I noticed a library was duplicated so I just left a comment about that.

[what-the-diff]

PR Summary

• Modernized Skin File Loading
  Added new code that uses an updated method, fs.readdirSync, to read skin files in the "resources/assets/less/skins" directory for dynamic handling. This helps us keep track of assets more efficiently.

• Optimized Style Sheets Processing
  Reduced complexity by removing multiple mix.less statements and replacing them with a loop for dynamic less file generation for every skin folder. This results in cleaner code and may potentially improve processing time.

• Improved JavaScript File Paths Handling
  Updated the file paths for some JavaScript files that are being combined using the mix.combine function. This change improves the organization and tool's ability to locate these files.

• Refined Indentation in Signature Pad Script
  Tweaked the indentation in the ./resources/assets/js/signature_pad.js file for better readability. While minor, well-formatted code makes future updates and bug fixing easier.