Add global emissions trajectories for concordia

[jkikstra]

Before being able to make a synthetic, comprehensive historical emissions dataset for concordia, we first still need to add global, total (no sectoral split), emissions trajectory data for HFC, C2F6, CF4, SF6.

Also, for CO2 AFOLU, we need global "Deforestation and other LUC" (gross emissions) and "Agriculture", as well as net CO2 AFOLU.

In addition, note that "Aircraft", and "International Shipping" (for all emissions species) will also only be processed at the global level.