fix: Branch blockers API extraction and processing

[ch097711]

Previously, branch_blocker information was parsed from summary.json. However, a previous commit moved the branch_blocker information to branch-blockers.json, but the parsing logic was not updated accordingly. As shown in the figure, this API has no return value.

Therefore, this PR fixes the parsing of branch_blocker data to now be extracted from branch-blockers.json.

[DavidKorczynski]

This looks good. I'm a bit unsure if we should land this because we're having some issues with storage size -- the branch blockers can be quite heavy and we need to watch out for taking up a lot of space.

[ch097711]

I noticed a comment in the extract_local_project_data function that seems to prevent saving blocker information via save_branch_blockers:

    # Dump things we dont want to accummulate.
    #save_branch_blockers(branch_pairs, project_name)

fuzz-introspector/tools/web-fuzzing-introspection/app/static/assets/db/web_db_creator_from_summary.py

Line 462 in b194efb

#save_branch_blockers(branch_pairs, project_name)

However, this line is not commented out in the extract_project_data function:

fuzz-introspector/tools/web-fuzzing-introspection/app/static/assets/db/web_db_creator_from_summary.py

Line 751 in b194efb

save_branch_blockers(branch_pairs, project_name)

If there's still a concern about storage and a need to prevent saving this blocker information, maybe we could comment out all calls to save_branch_blockers. I could then add a note to the documentation for the branch_blockers API to clarify that.

Thanks!