Create separate sample_data_type records for different sections

[djwooten]

PR Checklist

• This comment contains a description of changes (with reason)
• Referenced issue is linked
• If you've fixed a bug or added code that should be tested, add tests!
• Documentation in docs is updated
• docs/changelog.md is updated

Description of changes

• Fixes Bug report - sample_data sometimes references incorrect sample_data_type entries #530
  • When handling a report, megaqc checks to see if that SampleDataType already exists. However it only checks on the basis of data_id, but ignores data_section. Therefore if multiple report types (data sections) reuse the same data_id, currently this will reuse that SampleDataType even if data_section is wrong for the incoming report.
• This PR adjusts the logic so that it checks for previous SampleDataType entries based on data_key, which includes both data_id and data_section.