Geo: Allow enabling of Object Storage replication via API/Command Line

Description

Enabling Object Storage replication is required to setup a fully functioning Geo Deployment. Currently we document how to enable this within the UI but we have no solution for enabling this via an API or CLI. With the aim of enabling this in a Geo Deployment that have been configured via the GitLab Environment Toolkit some form of API/command line process for enabling this would be required.

Proposal

Add the ability to run a single command/API request to enable/disable Object Storage replication.