SQLServer: The service_ensure parameter in the type is not implement in the provider

The service_ensure parameter in the type is not actually implemented in the sql_instance provider

Type
https://github.com/puppetlabs/puppetlabs-sqlserver/blob/06a8ed9a3ecef1b6abcaca15a8173d0e982ee8b2/lib/puppet/type/sqlserver_instance.rb#L47-L50

We should either remove this param or implement it (and test for it) in the provider.