[Feature] Support for images in PDF format

[Udayraj123]

Is your feature request related to a problem? Please describe.
It appears that existing commercial products use PDF as the format for processing OMRs. Supporting this in OMRChecker will help with making it easy for adoption.

Describe the solution you'd like
Use a popular pdf reading library to convert the pdf into jpg image and then forward that image to the existing solution. This can be implemented as a plugin as well (discussion needed).
We can also support multi-page pdfs this way: tracked in a separate task: #145

Describe alternatives you've considered
Currently we would need to use third party bulk converters to achieve this.

Additional context
NA

[codesleep-Beperfect]

Hi, Can I solve this issue for JWOC?

[Udayraj123]

Hi @codesleep-Beperfect , please refer to this comment

#123 (comment)

You may choose to build on top of that solution. I can assign it to you for now