Fix security vulnerabilities

[yensung]

Description

https://github.com/allenai/scholar/issues/29403

• Upgraded @types/react-pdf to 5.7.2 (same with react-pdf)
• PDFDocumentProxy is imported from react-pdf instead of pdfjs-dist to avoid ts-lint errors
• Added --exit at the end of yarn test command to jump out of ts-mocha when finishing running all tests

Testing Plan

• yarn audit reports no vulnerable package
• Unit tests are run successfully without errors
• lib and the whole docker container can be successfully built
• Newly built pdf-component.js, pdf-component.css, and index.d.ts can be used on S2 without any errors