fix: fully escape string for usage in require call

[marvin-roesch]

I was trying to use this loader in a project of mine and ran into some issues with certain file names I'm trying to load. Specifically, I have images whose file names contain single quotes '. This package would insert them into the generated require call as-is, leading to a parse error later on.

As the package cannot control the file names it receives, it has to take care of fully escaping the string spliced into the generated module code. I have used the js-string-escape package for this, but the escape function is simple enough that it could also just be included in this package.

[Calvin-LL]

Thank you ❤️

[Calvin-LL]

I'll publish the update in an hour