fix: bug introduced in 7f6c3cda

[nikbpetrov]

No description provided.

[houtanb]

@nikbpetrov there's another bug with this code.

Specifically, _build_question_bank() from orchestration/_io.py does if "hash_mapping.json" not in filename on line 164, but the change in 7f6c3cd stopped creating this file. Now, when a hash mapping is created, it's in hash_mapping_<source>.json

Please:

1. confirm that the hash mappings that are created are identical between the ones with _source.json and the original ones for all sources that create a hash mapping. These only exist for ACLED and Wikipedia I believe.
2. fix this and add on top of this create a new PR. What was the reasoning for changing this in the first place?

[houtanb]

Merged in 02fda0c and ee93a00