[feature] Optimize get_daily_irradiation_map()

Summary

The method takes a lot of time and we should try to optimize it.

Current behavior

Among other things, the conversion from dictionary to numpy arrays at the end of the method takes a convoluted approach : pd.DataFrame.from_dict(irradianceMap_diffus).to_numpy().

Desired behavior

This specific point could be handled more efficiently by directly converting from dict values to numpy array, instead of taking a detour through a pandas dataframe.

See "Sources" section below for a detailed example.

Sources

Convert dictionary values to numpy array :

You can use fromiter to get the keys and values into an np array:

import numpy as np

Samples = {5.207403005022627: 0.69973543384229719, 
        6.8970222167794759: 0.080782939731898179, 
        7.8338517407140973: 0.10308033284258854, 
        8.5301143255505334: 0.018640838362318335, 
        10.418899728838058: 0.14427355015329846, 
        5.3983946820220501: 0.51319796560976771}

keys = np.fromiter(Samples.keys(), dtype=float)
vals = np.fromiter(Samples.values(), dtype=float)

print(keys)
print('-'*20)
print(vals)

Linked features or branches

#117