Add different variations of PhAlkEthOH datasets

[chrisiacovella]

Currently the PhAlkEthOh dataset comes from the OpenFF optimization dataset and contains the entire optimization trajectory for each unique molecule.

It would be good to have a few additional variations of this dataset for exploring various aspects of the different NNPs and how data generation strategies impact efficacy. A few additional "versions" to add for the existing dataset:

• The first (rdkit generated) configuration
• The first (rdkit generated) and last (energy minimized) configurations in the trajectory.
• The first few configurations in the trajectory; this would replicate the idea of just doing a few steps of optimization.

Related, I will work on getting additional calculations going using the trajectories generated with GAFF.

[chrisiacovella]

This was mostly addressed in PR #245 . This PR removed configurations with high forces (about 1 hatree/bohr, just like done in spice). This also generates a test/full dataset that only contain the final energy minimized configuration, to make something that is very similar to qm9 (but with forces). This can serve as a baseline for also seeing importance of a few steps of optimization, MD generated configurations, etc.