add power supply and transmission overheads to OperationalEmissions

[dpol1]

As discussed in the issue #153, this PR adds the new overhead factors to the OperationalEmissions module to properly account for power supply and transmission losses.

Changes included:

• Added powerSupplyEfficiency (default 1.04) and powerTransmissionLosses (default 1.08) variables to the OperationalEmissions class.
• Introduces the ability to set powerSupplyEfficiency and powerTransmissionLosses via the init method. This allows for runtime configuration of these values, improving flexibility for operational emissions calculations.
• Updated the enrich() method to include these new factors in the final emissions calculation (emissions = energyUsed * carbonIntensity * totalOverhead).
• Updated OperationalEmissionsTest to expect the new computed values, adding a 0.0001 delta to assertEquals to correctly handle floating-point precision differences.
• Update the docs for the module

[jnioche]

Thanks @dpol1, this is a good start!
Please modify the part of the documentation that describes the module + explain what we mean by these two things.
The values should also be taken from the configuration as part of the init like done in pretty much every other module. As for adding get() / set(), this is not how the configuration works, see for instance ConstantLoad
Thanks!

[jnioche]

thanks @dpol1
I will add the params to the default config file for consistency and as a way of documenting