Various data quality improvements

[CattMarlin]

• Edits stemming from a review of the data against Ballotpedia race totals.
• Various OCR fixes

[github-actions[bot]]

Thank you for your contribution! Our file_format test detected some potential issues in the files you added.

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FAIL: test_format (data_tests.test_data.FileFormatTests.test_format) [2018/counties/20181106__ca__general__san_bernardino__precinct.csv]
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* Header ['', 'county', 'precinct', 'office', 'district', 'party', 'candidate', 'votes'] has empty entries.