General PDF text extraction and cleanup

[swotai]

This ticket is to start working on some organized way to read files from GDrive, PDF text extract, and data cleaning, to be fed to the keyword extractor/summarization pipelines.

notebook has code for keyword extract.

TODOs:

• [ ] Refactor the part for reading google drive files into a separate script/function
• [ ] PDF Extraction
• [ ] Cleanup and improve on text extraction