Draft: Develop Cherenkov emission module

Closes #275

Here is the first official version of cherenkov emission module. 2 versions are available : Cherenkov and CherenkovToolBox.

CherenkovToolBox uses Corsika 7 input to generate photons and ables to compare Corsika 7 Cherenkov module with Corsika 8 Cherenkov module with close algorithms whereas Cherenkov uses Corsika 8 experiments with for the moment close algorithm with some modifications. For this version, the model is Corsika 7 for calculation algorithms.

The 2 modules uses for the moment an Atmosphere Tabulated to propagate photons. A Telescope Grid class generates a grid of telescopes and sort photons by telescope. Some examples are used :

• cascade_example_cherenkov_tabulated_corsika7 : CherenkovToolBox
• em_shower_cherenkov_tabulated (with input file) : Cherenkov with an input file to test different experiments easily in em cascade

You can save with these modules photon positions, directions, arrival time,... And keep photon information by telescope in output screen.

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ps: Just changed the branch's name