[FEATURE] Include planned transmission lines

[trevorb1]

Idea

During processing of the electricity transmission line connections, we filter out about 50 planned or subsea connections (such as TRNCHNSDKORXX) that don't have associated capacities. It would be nice to include these as expansion options.

Is your feature related to a bug?

No response

Suggested Soltuion

The costs/efficiencies associated with these lines exist in the input PLEXOS files. We just need to change the filtering to keep them, and assign a residual capacity of zero to them.

Additional Info

I'm pretty sure this is where the filtering of transmission lines happens in OPG_powerplant.py

https://github.com/OSeMOSYS/osemosys_global/blob/20a270025cb914e72b56c7d92d114933671527a7/workflow/scripts/osemosys_global/OPG_powerplant_data.py#L766-L770