introduce basic fact collection

client/vendor/github.com/zcalusic/sysinfo/kernel_darwin.go

@@ -0,0 +1,14 @@
+//go:build darwin
+// +build darwin
+
+package sysinfo
+
+// Kernel information.
+type Kernel struct {
+	Release      string `json:"release,omitempty"`
+	Version      string `json:"version,omitempty"`
+	Architecture string `json:"architecture,omitempty"`
+}
+
+func (si *SysInfo) getKernelInfo() {
+}