Update Generator Capital Costs Results Plot to include EGS

[ktehranchi]

Checklist

• [X] I am running on an up-to-date pypsa-usa environment. Update via conda env update -f envs/environment.yaml

Issue exisits on what branch

Develop, Other

The Issue

MJ is implementing EGS and it is not showing up in the results plot for capital costs.

Steps To Reproduce

No response

Expected Behavior

No response

Error Message

No response

Anything else?

No response