LAMMPS IO: update parse_lammps_log for thermo_style yaml

[rkingsbury]

Is your feature request related to a problem? Please describe.
The format of data output by LAMMPS is completely dependent on what a user specifies in the input file, making it difficult to parse the output text files in a robust way.

Describe the solution you'd like
LAMMPS has recently introduced thermo_style yaml to enable outputting formatted thermodynamic data (see discussion post and documentation page). It would be great to update the associated pymatgen output parsers to take advantage of this. Specifically, parse_lammps_log.

The high throughput MD development team (myself, @manaslkht, @orioncohen, others) will put this on our roadmap as a future enhancement