Add functionality in convert_output for Rceattle #208
Description
Convert the output from the Rceattle model output object made in R to the standardized format
Development Needs
- transform necessary data to long format
- Add eras into the conversion
- standardized current naming conventions to match those in other converted model output
- add test for Rceattle conversion
- (Potentially) add Rceattle converted output as another example dataset in the package