Add script to update `load_curve_annual` in the `*_sb` releases

[alexhyunminlee]

What

Add a step in the ResStock data prep pipeline that updates the load_curve_annual files based on the load curve adjustments made in the *_sb release creation.

Why

We need to use the updated natural gas consumption when classifying MD's Chesapeake utility's gas tariff rate assignment.

How (optional)

Deliverables

• New step in the *_sb release prep for adjusting the annual load curve files
• Use the *_sb release when assigning tariff keys in the MD gas tariff mapping script.

[linear]

RDP-240