Provide for project level backup of redcap data

[pbchase]

Provide for project level backup of redcap data

[pbchase]

Backup method

I've gone back and forth on the type of incremental backup we should make. The choices are to read the log data via the API (see OuhscBbmc/REDCapR#320), read the log data directly, or read the updated records via redacp_read. After much vacillation, I think the best approach is redcap_read, while reading record deletion data from redcap_log_read.

Pros

• Full backups and incremental backups of a project to be made 100% via the API if an API token is available.
• A full restore dataset could be reconstructed by binding date-stamped rows, sorting by date, distincting, and then removing any rows that pre-date their deletion.
• At point-in-time restore can be created by filtering the data fed full-restore process.
• Each backup file is in the appropriate format for REDCap data input and redcap_write.
• Each backup file is restorable without processing.