ssm-browse: new utility to browse SSM parameters

This is more of an exercise to work out how best to use controllers

internal/ssm-browse/models/models.go

@@ -0,0 +1,10 @@
+package models
+
+type SSMParameters struct {
+	Items []SSMParameter
+}
+
+type SSMParameter struct {
+	Name  string
+	Value string
+}