Call a Remote Function Module (RFC) From SAP Cloud Platform ABAP Environment

First some important prerequisites (because I noticed these myself just late somewhere in the fine print after spending [wasting] some time trying things in my own trial accounts)

◉ You need a Global Enterprise Cloud Account – i.e. not just a trial account
◉ You need this for both, the SAP Cloud Foundry and the SAP Cloud Neo environment
◉ SAP Cloud Foundry and the SAP Cloud Neo need to be in the same region