Dask integration v2

[GintasS]

A version of dask integration with the logic following: https://stackoverflow.com/questions/71874244/using-dask-to-fill-boost-histograms-stored-in-class-in-parallel .

Issues:

• The charts are not the same as per the original uproot example. My implementation (like the StackOverflow one) is based on the fact that the histogram is only filled once. The original (uproot) example fills the same histogram multiple times
• self.h_n histogram does not work, need to investigate.

The solution works like this:

1. Reads .ROOT files sequentially.
2. Computes histograms by lazily creating the whole histogram object at once (all_histogram_actions_TH1F function). This function produces dask-delayed objects. All of these dask-delayed objects are then aggregated via computeHistos.
3. Calling dask.compute() on the histograms.
4. Writing histograms via the old writeHistos function.

Performance sheet: