[FEATURE] Use console.warn to emit errors not console.error

[hisham]

Is your feature request related to a problem? Please describe.

When this library emits warnings like "warning: PDF stream Length incorrect", it emits them in console.warn rather than console.error, but handles the PDF succesfully. We have alarms setup on our server to alarm when there is console.error messages. So this triggers false alarms.

Describe the solution you'd like Use console.warn for warnings, and console.error for errors (or throw exception on error)

Describe alternatives you've considered Monkey patch console.warn in our code.