Modify `OptSchema` so the `fmax` attribute is less prone to misinterpretation

[Andrew-S-Rosen]

What new feature would you like to see?

https://github.com/Quantum-Accelerators/quacc/blob/800a94f0d0525fb5ca83610905cf0411800321b3/src/quacc/schemas/_aliases/ase.py#L37-L45

The OptSchema has fmax as a primary key. This might make users think that it is the maximum force from the end of the run rather than the Optimizer.fmax attribute (i.e. the fmax: float keyword argument passed to the Optimizer.run() method). It is probably worth adjusting the OptSchema to prevent confusion on this point, although this would be a breaking change.