Improved configuration parsing

[sarthakpati]

Is your feature request related to a problem? Please describe.
Currently, the configuration parsing is done by a single submodule [ref], which is creates issues with maintenance as more functionality is introduced.

Describe the solution you'd like
Using a configuration validation mechanism that is more standardized would make the developer and user experience much better. Some examples are (and this is by no means an exhaustive list):

Package	Documentation	Example
Cerberus	https://docs.python-cerberus.org/	https://stackoverflow.com/a/46626418
PyDantic	https://docs.pydantic.dev/latest/	https://stackoverflow.com/a/61021183
Marshmallow	https://marshmallow.readthedocs.io/en/stable/	https://stackoverflow.com/a/63739747

Describe alternatives you've considered
N.A.

Additional context
It would make sense to eventually move GaNDLF's various functionalities to something like Hydra, and this could potentially be a good starting point.

[vedik2002]

Hi @sarthakpati can you please assign this issue to me.

[sarthakpati]

Thanks, done.

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[sarthakpati]

Hi @vedik2002, are you still working on this?