Preprocess Iowa PDFs

[ghing]

This work will be done over in https://github.com/openelections/openelections-data-ia

Subtasks:

• [x] Preprocess 20010612__ia__special__general__state_house__85__county.pdf
• [x] Preprocess 20010612__ia__special__general__state_senate__43__county.pdf
• [x] Preprocess 20011106__ia__special__general__state_house__82__county.pdf
• [x] Preprocess 20020122__ia__special__general__state_house__28__county.pdf
• [x] Preprocess 20020219__ia__special__general__state_senate__39__county.pdf
• [ ] Preprocess 20021105__ia__general__precinct.pdf
• [x] Preprocess 20030114__ia__special__general__state_senate__26__county.pdf
• [x] Preprocess 20030211__ia__special__general__state_house__62__county.pdf
• [x] Preprocess 20030805__ia__special__general__state_house__100__county.pdf
• [x] Preprocess 20030826__ia__special__general__state_house__30__county.pdf
• [x] Preprocess 20040203__ia__special__general__state_senate__30__county.pdf
• [x] Preprocess 20091124__ia__special__general__state_house__33__precinct.pdf
• [ ] Preprocess 20100608__ia__primary__county.pdf
• [x] Update PreprocessedResultsLoader, if needed, to reflect any quirks or differences in newly preprocessed results files