data: upgrades to eastern transmission for base case feasibility

[danielolsen]

These changes obtain feasibility for the Eastern base case. The first four changes (by branch ID) achieve general feasibility with the scaled-up generation capacity: ensuring that there is no conflict between generator Pmins and their associated transformer ratings (tested in Scenario #307). The rest of the changes achieve feasibility through the summer months without any load curtailment, and were tested in Scenario #308 and #309. For each branch, the rateA field is multiplied by a scale factor, and the x field is divided by the scale factor (as branches are scaled in the change_table).

new_transmission_upgrades = {
    # Pmin feasibility
    8446: 2,
    8699: 2,
    11516: 2,
    20658: 2,
    # Peak load feasibility
    35404: 1.1,
    38927: 1.1,
    41715: 1.1,
    78211: 1.4,
    78213: 1.2,
    78236: 1.2,
    78237: 1.2,
    78238: 2.1,
    78266: 1.1,
    78270: 1.2,
    78271: 1.1,
    78299: 1.1,
    78435: 1.1,
    78470: 1.1,
    }

See: https://github.com/intvenlab/RenewableEnergyProject/issues/193

[BainanXia]

It looks good. Great work!