Convert Stata-based PII scan into R-based PII scan

[larsvilhuber]

• write a script (bash) in tools/ that uses R and the code at https://github.com/J-PAL/PII-Scan to parse a directory and scan all data files for PII. First argument to script should be the directory. Output should be similar to the existing Stata-based PII scan.
• Integrate the R-based scan into the Bitbucket workflow. Initially, do not replace the Stata scan, but run both. Outputs should not overwrite each other.
• Adjust the integration of the R output into the REPLICATION.md to replace Stata immediately.