New feature: support timedelta as limit when using interpolate method=time

[bertrandhaut]

When we call the interpolate function based on time, it would be useful to be able to give a limit expressed as a timedelta (instead of a number of row).

Use case

• I've a time series measurement of temperature in function of time. The measurements are not performed at a constant frequency
• I want to interpolate missing data if the interpolation period is less than 1 hour.

[shoyer]

This is similar to the proposed tolerance argument for reindexing (#10411) -- I suspect the implementation would be pretty similar.

For now, you can work around this by first resampling to a constant time interval, and then applying the interpolation.

[mroeschke]

Seems like there hasn't been much interest in this feature over the years so closing