Re-group ensemble and data assimilation inputs

[stvdwtt]

Currently, the input parameters controlling the standard deviation of model parameters for ensembles and whether or not to include them in augmented states are grouped in the "ensemble" and "data assimilation" input blocks. This is not desirable since it splits up where nominal parameter values are defined and where other attributes of that parameter are defined. Therefore, these should be moved to the appropriate "beam" or "material" blocks. It also simplifies setting these ensemble/data assimilation parameters for multiple heat sources and/or materials.

Along with this, we should implement a more flexible and scalable approach for parsing and handling the augmentation parameters. The enum class AugementedStateParameters in DataAssimilator.hh is heavy-handed, and promotes specifically enumerating which properties (of which beams/materials) can be used in augmented ensembles.