Clean up `generation_projects_info` organization and loading

Currently, generation_projects_info.csv is one big file that contains info for both generators and storage, meaning that there are unnecessary columns for storage that must be filled in for all generators.

In addition, this file is currently loaded into the build module, even though many of its parameters are used in dispatch. Additionally, the storage module also independently loads the storage columns from the file.

To fix the loading issue:

[x] move the parameters that are only used in the dispatch module from build to dispatch. This will mean reading the file separately, and also moving the parameter definitions.

To fix organization:

[x] Order the columns in the input spreadsheet by what they are used for: build, dispatch, storage, inputs, etc
[x] Add a header row to the inputs spreadsheet (that is not read) that explains the category for each variable?

To fix the storage issue:

[x] Consider moving storage projects to a separate input file storage_projects_info
[ ] If we do this, we have to consider how this affects setting: either we need to manually make STORAGE_GENS a subset of GENERATION_PROJECTS, or we need to re-index all things that use GENERATION_PROJECTS.
[ ] GENERATION_PROJECTS could fill the role of NON_STORAGE_GENS
[ ] We would need an overall SET for all generators and storage (or do we? What is this used to index?)
[ ] Move ppa_capacity_cost to a storage-only parameter.

pencleanenergy / MATCH-model

Clean up `generation_projects_info` organization and loading #51