feat: endpoint for serving PDF report

Description

• Add an API endpoint serving PDF report for Recurrence Run and Recurrence Trends
• Refactor report:
  • Split original *Report into CSV and JSON reports
  • Add PDF report
  • PDF and CSV reports inherit from corresponding JSON report
  • Caching is handled in JSON report
  • Put reports related source code files under a separate folder: report
• Add tests

Supporting information

• Ticket: BB-6385

Testing instruction

• Checkout the branch in local environment
• Create data necessary for testing
  • Team
  • ChecklistDefinition: includes all types of interfaces
  • Recurrence
  • Run
• Complete some checklists of a Run
• Go to Swagger page
• Call API to get Recurrence Run report, PDF format
• Call API to get Recurrence Task Trends report, PDF format
• Make sure files downloadable and display properly

Side note

• Suggested number of team members: 4 or more

Proof of Work

• Generated Recurrence Trends report: report_trends_NlWsm2XwTduA.pdf
• Generated Recurrence Run report: recurrence_NlWsm2XwTduA_run_hECsLx6QQFqA_report.pdf
• Flow: https://www.loom.com/share/d9170fe8530f4261bce2027e1f3712ee