Add Forcing Engine CI/CD Job and Realization Config Option

This PR resolves #762 and resolves #763.

Additions

Adds test_forcing_engine_integration to module integrations. This job runs the test_forcings_engine unit test executable.
Adds a branch in Formulation_Constructors for a ForcingEngine option. Currently, this throws a runtime error.

Depends on #720.
Implement full logic for constructing a forcing engine data provider.
Determine best approach for required GRIB files. (i.e. store in repo, extract on-demand, etc.)

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