Water and Airflow parameters - Sum total tool unit fix

[spfromowitz]

Is your feature request related to a problem? Please describe

Yes - when using an airflow (units CFM/FT^3) or water flow (units GPM) parameter with the sum total tool.

When selecting parameters, it scales them to a different unit.

Example: 2 families selected for airflow. "AirflowMax" = 100, 200. Total should be 300, but it outputs as 5. (x60 difference every time)
Example: 2 families selected for water flow. "HotWaterCoilFlow" = .704, 1.203. Total should be 1.907, but outputs as 0.00213 (x887.5 difference every time).
## Describe the solution you'd like
Either 1 of 2 options:

1. A "simple sum total" mode where anything that detects as a number regardless of parameter type will just sum the raw numbers
2. An option menu for sum total where you can select the default units the pyRevit should assume the answer should be in where the user can configure this as needed.

see above

Describe alternatives you've considered

n/a

Additional context