Rework session handling to prevent cyclic import

imports github.com/RafayLabs/rcloud-base/internal/fixtures
imports github.com/RafayLabs/rcloud-base/pkg/service
imports github.com/RafayLabs/rcloud-base/pkg/auth/v3
imports github.com/RafayLabs/rcloud-base/pkg/service

pkg/common/constants.go

@@ -47,6 +47,4 @@ const (
 	RelayCommandsAuditType = "RelayCommands"
 )
 
-type contextKey struct{}
-
 var SessionDataKey contextKey

pkg/common/types.go

@@ -24,3 +24,5 @@ type CliConfigDownloadData struct {
 	Organization string `json:"organization"`
 	Partner      string `json:"partner"`
 }
+
+type contextKey struct{}