Reorganize Corpus Tester

[cwfitzgerald]

Both the bve-parser-run tool and the bve-corpus tool contain a lot of duplicate code that should be cleaned up, as well as some general technical debt that should be repaid.

This also relates to their interface and presenting a way to generate and compare reports between corpus runs.

Notable features:

• Add tool to compare corpus dumps.
• Add tool to search through corpus dumps
• Make error representations more structural and not piles of text.
• Allow partial corpus runs.
• Normalize all filenames.