Refactor test package and some field types

Fairly big test refactor and changing some of the fields from pointers

test/valid-config-default-values.hcl

@@ -0,0 +1,11 @@
+check_interval = "1s"
+default_alert_down = ["log_command"]
+default_alert_after = 1
+
+monitor "Command" {
+  command = ["echo", "$PATH"]
+}
+
+alert "log_command" {
+  command = ["echo", "default", "'command!!!'", "{{.MonitorName}}"]
+}