Expand H2Integrate's postprocessing utilities

[johnjasa]

Expand H2Integrate's postprocessing utilities

There are existing postprocessing functions that we can use within the new H2Integrate framework.
However, these existing functions assume that we have almost all physics and cost results available to us.

Proposed solution

We should investigate if we want to keep using that system and pass those resulting objects into the postprocessing routine, or if we should expose the needed outputs to OpenMDAO and use the CaseRecorder to produce an output file that can later be read in and postprocessed.
I'm leaning towards the latter as it would allow a case to be run, then postprocessed independently after the fact.
However, this would take some reconfiguration of the postprocessing utilities, as well as exposing all necessary outputs in each of the technology models.
This might be a net positive, though, and serve as a good example of how to output results from technology models and how to access them.

Alternatives considered

Additional context

[johnjasa]

Bumping this as important; at the very least, adding an example in the docs about how to access the .sql file is a low-hanging and valuable fruit

[johnjasa]

Mostly achieved through a few different PRs, like #330 #366 #440