Draft: Code refactor database build

Hi everyone,

I welcome you to give a look to this merge request and feel free to give any advice for improvements

This merge request contains the following codes:

cell_build_processing.py: Module with functions to handle raster data and create vectorized cells. It works with data from OBM, GHSL and WSF.

pickle2db.py: (experimental) im working on an optimal way to push results to the SQL database (not a final result)

scripts directory: contains multiprocessing scripts with the necessary tweaks to create pickle files from each method. Here I integrated the OBM roads database as well