[Debugify][OriginalDIMode] Update script to handle large JSON reports

This patch updates llvm/utils/llvm-original-di-preservation.py to create more
compact HTML verify-debuginfo-preserve reports by:
- removing duplicated debug info bugs,
- introducing -compress option to create highly compressed report.
Additionally, this patch makes script able to process very large JSON inputs.
That is done by reading & analyzing JSON report in chunks.

Differential Revision: https://reviews.llvm.org/D115617