Extend detect_clearsky for different data periods

[cwhanse]

The threshold parameters for pvlib.clearsky.detect_clearsky were calibrated using data at 1 minute intervals. Recently, Jordan and Hansen [1] showed how to extend the detect_clearsky function for time-averaged data out to 30 minute intervals. The extension requires different data window length and different values for the threshold parameters, but doesn't require any change to the parameter calculations. Interestingly, the threshold values are linear functions of the data interval.

Describe the solution you'd like
Implement a helper function for detect_clearsky that infers the parameter values from the input data interval.

Describe alternatives you've considered
Leaving as-is.

Additional context

[1] Jordan, D.C. and C. Hansen, "Clear-sky detection for PV degradation analysis using multiple regression", Renewable Energy, v209, p. 393-400, 2023.