text: Title: Sliding window (mix of rolling and coarsen)
  Body: ### Is your feature request related to a problem?
  
  I often have functions to apply to sliding windows, such as a fft computation, but both coarsen and rolling do not fit. For example, generating a spectrogram with overlap between windows is complicated using xarray. Of course, one could use  [scipy STFT](https://docs.scipy.org/doc/scipy/reference/generated/scipy.signal.ShortTimeFFT.html)  if we consider the example of the spectrogram, but one still needs to manage the coordinates manually.
  
  
  ### Describe the solution you'd like
  
  A new window function that combines rolling and coarsen. The new window would have the current dim parameter of rolling and coarsen split into two:
  - window_size: the size of the window (equivalent to the current value of the dim parameter)
  - hop: how much do we shift in between each window (see the hop parameter of [scipy STFT](https://docs.scipy.org/doc/scipy/reference/generated/scipy.signal.ShortTimeFFT.html) for example).
  - perhaps we could add a window function to apply, but this is not necessary as this can be done without.
  
  This unifies rolling and coarsen as rolling is simply hop=1 and coarsen is hop=window_size.
  
  As for the implementation of this datastructure, I suspect we could use [as_strided](https://numpy.org/devdocs/reference/generated/numpy.lib.stride_tricks.as_strided.html) for very efficient implementation of construct.
  
  ### Describe alternatives you've considered
  
  - Using rolling + sel to only pick the windows with the correct hop, but this seems extremely inefficient
  - Handling the coordinates manually...
  
  ### Additional context
  
  _No response_