Fan control using selectable temp inputs

https://rusefi.com/forum/viewtopic.php?f=5&p=46931&sid=f921b803c90c0915bed08925911f48ba#p46931

Proposal for added feature:

Include sensor input selection for "Fan 1" and "Fan 2" control, so that the fans can be controlled with respect to not just CLT, but also oil temp or other useful temperatures.
Input source drop-down list could include: "CLT", "AuxTemp1 sensor" and "AuxTemp2 sensor".

One use case where this feature may be useful is on aircooled engine setups that has additional oil coolers with fans.

This would be useful on Harley thanks to 90% of them doing oil cooling.