Make SMS integration configurable via UI

Currently the SMS integration can be only configured by the Operations team.

Integration for OpenIT can be configured through UI but is not supported anymore.

sms77.io is supported but cannot be configured through UI.

Telstra administrator needs to be able to configure the SMS at the tenant level

global settings at the management tenant. if you have a need for smartrule to send sms, but it needs to be configured at tenant level for smart rule to work and currently is only available via an API not a user interface which is what Telstra need. It is the same SMS provider they just do not want to have to create it via an API.