Automatic service lookup during removal

Impact on the user
Unnecessary steps are required due to being forced to lookup either the service name or ID

Steps to reproduce

• Register a new PMM agent using pmm-agent setup, or similar
• Add a single service (mysql, mongodb, postgresql, proxysql, haproxy, external) using pmm-admin add of one or more types, maintaining a 1:1 ratio of instance:service-type
• Remove one of the services with pmm-admin remove <service-type>

Actual result
An error occurs and the user is forced to either know or lookup the service-name or service-id to successfully perform the operation.

Expected Result
The agent knows (runtime) or can lookup the necessary information on behalf of the user and save them the effort.

Details
When any service-type exists in a 1:1 ration for an instance of pmm-agent it seems unnecessary to force the user to know, or lookup the service-name or service-id in order to be able to remove that service. The agent should perform a lookup of its own services (either via the server or via runtime configuration) and only force the user to specify the service-name or service-id when more than one instance of a service is registered to the agent.