Add a postprocessing method for making stacked line charts for price breakdowns for DOEs

[johnjasa]

Add a postprocessing method for making stacked line charts for price breakdowns for DOEs

@jmartin4u made some cool plots using the price breakdown across a parameter sweep for iron.
He did it by outputting the data and reading it into Excel but we should implement a more general solution here.

Proposed solution

Let's make an function or method that folks can call after a DOE run.
It could:

• read in the parameter sweep info
• take in a user arg for the x-axis variable
• made a stacked shaded line chart for the LCO commodity

Alternatives considered

Additional context