Improve the ecological analysis method

[mzy2240]

1. Reduce the number of conditions by using formatted string

e.g.

if target == 'MW':
    flow = gen.loc[i, 'GenMW']

can be optimized into

flow = gen.loc[i, f"Gen{target}"]

2. When computing the EFM, compute the line flow and the loss induced EFM together

3. Use loc instead of column + index to access cells for better readiness and performance