OptimizableBatch and stress relaxations

[lbluque]

Add functionality to include cell relaxations in structural relaxations for models that implement stress prediction. This PR also enables batch calculations with ASE optimizers.

• Extends the OCPCalculator to enable stress predictions, and relaxations with ASE filters.
• Extends core.common.relaxation.ml_relax to enable batch relaxations including stress.
• Includes a new class OptimizableBatch that can be used with ASE optimizers or with the existing LBFGS implementation
• Includes a UnitCellOptimizableBatch to allow batch stress relaxations
• Includes a ExpCellOptimizableBatch to allow batch stress relaxations will do this in a separate PR

TODO

• Unit tests (missing tests with unit cell relaxation, pending models that can predict stress)

[codecov]

Codecov Report

Attention: Patch coverage is 64.54294% with 128 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
...m/core/common/relaxation/optimizers/optimizable.py	56.11%	104 Missing ⚠️
...c/fairchem/core/common/relaxation/ml_relaxation.py	18.18%	18 Missing ⚠️
src/fairchem/core/common/relaxation/ase_utils.py	86.66%	4 Missing ⚠️
...m/core/common/relaxation/optimizers/lbfgs_torch.py	98.11%	1 Missing ⚠️
src/fairchem/core/datasets/ase_datasets.py	50.00%	1 Missing ⚠️

Files with missing lines	Coverage Δ
src/fairchem/core/common/relaxation/__init__.py	100.00% <100.00%> (ø)
...chem/core/common/relaxation/optimizers/__init__.py	100.00% <100.00%> (ø)
src/fairchem/core/models/base.py	88.40% <100.00%> (-0.09%)	⬇️
src/fairchem/core/trainers/base_trainer.py	87.61% <100.00%> (-0.31%)	⬇️
src/fairchem/core/trainers/ocp_trainer.py	69.02% <100.00%> (ø)
...m/core/common/relaxation/optimizers/lbfgs_torch.py	98.11% <98.11%> (+82.35%)	⬆️
src/fairchem/core/datasets/ase_datasets.py	87.09% <50.00%> (+0.27%)	⬆️
src/fairchem/core/common/relaxation/ase_utils.py	81.48% <86.66%> (+19.52%)	⬆️
...c/fairchem/core/common/relaxation/ml_relaxation.py	26.00% <18.18%> (-1.78%)	⬇️
...m/core/common/relaxation/optimizers/optimizable.py	56.11% <56.11%> (ø)

... and 4 files with indirect coverage changes