Merge Vincent modifs

See merge request auclairj/modspa-pixel!1

run_samir() operational. Outputs are not yet valid, updated dev_samir_xarray.ipynb for comparison with modspa excel and added validation inputs and outputs for comparison.

run_samir() operational. Outputs are not yet valid, updated dev_samir_xarray.ipynb for comparison with modspa excel and added validation inputs and outputs for comparison.

Changed weather data loading to geotiff (can't find tool to convert tif to netcdf for large datasets), rewrote some function description, minor refactoring.

Modified input calculations. Reprojection of weather dataset needs to be handled differently for bigger images (with OTB for example). Modified the parameter class. Begining to work on samir time loop, inputs and parameters are done. Added env file. New method for calculating ET0 with xarray might have been found.

Calculation of ndvi cube and weather cube operational. Starting the samir params handling and time loop architecture