Pixel poligonization and database
In this MR I included a step that transforms specific pixel values (found in built_pixel_values attribute for DataSource) into a polygon.
Also introduced the DataBase class that shall be further used to request roads data and also pushing results from this program into the final DB (I could not get the mocking to work so there are no tests here)
PD. sorry for the delay on creating the MR, I discovered that polygons are created with different point orders on different machines.