Add organizational agent-cluster-mapping rules

app/policies/clusters/agent_policy.rb

...ment/namespace_cluster_agent_mapping_operations/create.rb

ee/app/policies/ee/organizations/organization_policy.rb

ee/app/policies/remote_development/agent_policy.rb

ee/app/policies/remote_development/group_policy.rb

ee/app/policies/remote_development/organization_policy.rb

ee/app/policies/remote_development/workspace_policy.rb

ee/lib/remote_development/README.md

...gent_mapping_operations/create/cluster_agent_validator.rb

ee/spec/policies/remote_development/agent_policy_spec.rb

ee/spec/policies/remote_development/group_policy_spec.rb

...c/policies/remote_development/organization_policy_spec.rb

ee/spec/policies/remote_development/workspace_policy_spec.rb

...cies/remote_development/workspace_variable_policy_spec.rb