Update test_read_las.R for working wrapped_data test

[dcslagel]

@Gitmaxwell,

This change enables the test for wrapped data to pass. The change adds a 2 new functions: .las_get_wrap()

• This gets the wrap flag from the ~Version section.

.las_get_wrapped_log_data()

• This parses and transforms the wrapped data so that it can create the required data string for data.table to read.

Let me know if this change could be accepted (or rejected) or needs some additional changes before being approved and merged.

Thank you,

DC