When project endpoint exists, import project data and geometries from kaavapino

[Rikuoja]

The Helsinki planning project API (https://github.com/City-of-Helsinki/kaavapino) contains data of current and upcoming (some non-public) projects that may start a Hearing.

Import all current and future projects (including non-public ones) that will yield automatically Hearing geometry, project phase data etc. once a Hearing is created for the project.

Requires #269 before implementing.