Add column to keep parameter

[leppott]

Is your feature request related to a problem? Please describe. Add a "columns to keep" parameter to ContDataQC() function.

Describe the solution you'd like Some users have fields they want to keep in the data.

Describe alternatives you've considered NA

Additional context Need to test if extra columns are kept or removed at each step of the process.

[leppott]

Only need to check QC and Aggregate

QC = extra columns are "dropped"

Aggregate = extra columns are "kept"