Code to generate SQL to import building footprints

[mdsimpson42]

This is the code, written by Mateusz, used to import building footprints into the database for use in the Colouring Cities Platform. This Python code will generate an SQL script, which can then be ran to import the data into the database.

I have added parameters for input and output filenames, so the user will need to edit the file to specify the location of the geojson file containing the footprints. They will also have to specify the location code for the area they want to import. It will then create the SQL script and save it in the same folder, generate_footprints.sql.

We should continue to iterate on this file to make it easier to use - for example, allowing the geojson filename to be passed in as a command line parameter. But for now, I am adding it to the project so that people have access to it to help get their platforms up and running.

See issue: #1421

[mdsimpson42]

Merging because we're just adding a new file to a new folder. This shouldn't affect the rest of the code.