Add control setting indicating which industries are subject to the carbon tax

[jrissman]

Currently, the carbon tax applied to the Industry sector affects all industries calculated in that sector, even agriculture and waste management. However, many real-world proposals that tax methane emissions exempt agriculture and waste management, and they (or other industries) might get special exemptions from the CO2 tax as well. Adding a control lever that indicates which of the Industry Categories are subject to the carbon tax could allow for more accurate simulation of carbon pricing that exempts agriculture, waste management, or other industries.

The control lever need not be a Boolean. If desired, it could be a multiplier between 0 and 1 that indicates the relative extent to which the carbon tax is levied on that industry. This would allow customization of the carbon tax rate for every industry individually.

[mkmahajan]

Added a time series control lever