Substitute Phase1 csv steps for direct R read with pajengr

[llnns]

After the paje sort, the following steps occur:
Use of pajeng to generate csv files.
Use of individual greps to split different Nature data.
Use of read_csv to read these files on R.

These three steps could be substituted by the use of pajengr.

[schnorr]

Problem is that in its current version, the pajengr package do not have support for --out-of-core capability of pj_dump, which basically means pajengr will load the whole trace in memory before returning. This is unfit for large traces.