helpers: provide a few generic helper functions

This PR deprecates some functions in favor of generic alternatives.

The new functions are compatible only with Nomad v1.4+.

The old functions (nor their use) should not be removed until Nomad v1.6+.

helper/pointer/pointer.go

@@ -0,0 +1,7 @@
+// Package pointer provides helper functions related to Go pointers.
+package pointer
+
+// Of returns a pointer to a.
+func Of[A any](a A) *A {
+	return &a
+}