text: Title: Investigate use of cast() in reports.
  Body: Investigate whether these instances of `cast()` are needed.
  PRs should be small (at most a few files).
  
  reports/graphs.py
  - https://github.com/capitalone/DataProfiler/blob/main/dataprofiler/reports/graphs.py#L77
  
  reports/utils.py
  - https://github.com/capitalone/DataProfiler/blob/main/dataprofiler/reports/utils.py#L53 