cloud: Split deployment control into functions instead of services

[spbnick]

At the moment, the deployment done with the cloud script can be split and controlled on Google Cloud service type boundaries (roughly). That was working quite well, but as the complexity of the deployment is growing, we need to consider splitting the deployment along functional boundaries. I.e. instead of "cloud functions", "pub sub", "postgresql", etc. split by function, such as "operational database", "archive database", "ingestion", "update processing", "notification generation", and so on.