Row count checks on final parquet, _metadata and ancillary files

[nevencaplar]

This is part of the verification pipeline tickets, connected with #344

Implement row count checks on

1. Final Parquet Files
   ● Get row counts from file footers.
   ● Compare total with truth.
   ● Compare per partition with intermediate files.
2. _metadata File
   ● Get row counts from _metadata file.
   ● Compare total with truth.
   ● Compare per partition with intermediate files.
3. Ancillary Files
   ● Check numbers in all ancillary files.
   ● Total in README.
   ● Counts per file/partition in csv files