New trajectory class with parquet rountrip functionality

[esoteric-ephemera]

In support of removing ionic step / calcs reversed info from MP's mongo task collection, this adds a Trajectory class which interfaces with pyarrow/parquet, pymatgen's Trajectory, and ASE's Trajectory. Verified that parquet rountrip works perfectly (model-dumped hashes of emmet Trajectory objects are identical before and after parquet conversion).

Since the site still needs energy convergence info, using parquet lets us partially retrieve the energy data from the trajectory

This is a middle-ground solution until the emmet-archival PR is ready

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 82.66667% with 26 lines in your changes missing coverage. Please review.

Project coverage is 90.05%. Comparing base (947ecc8) to head (6245477).

Files with missing lines	Patch %	Lines
emmet-core/emmet/core/trajectory.py	82.66%	26 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1206      +/-   ##
==========================================
- Coverage   90.13%   90.05%   -0.08%     
==========================================
  Files         147      148       +1     
  Lines       14506    14656     +150     
==========================================
+ Hits        13075    13199     +124     
- Misses       1431     1457      +26     

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[esoteric-ephemera]

@tschaume @yang-ruoxi : should be ready to test with the trajectories endpoint, roundtrip is working fine. Only additions I might want to make are supporting site properties, but I don't think we have any in the ionic steps (e.g., selective dynamics, magmoms, and velocities tags)

And @tsm when you have time : any comments about the parquet serialization are appreciated - this is a very specific implementation of parquet serialization for an emmet object