refactored MapIterator using an interface to support also Queue/Stack + tests

Signed-off-by: Simone Magnani <[email protected]>

Author: smagnani96

examples/README.md

@@ -21,7 +21,6 @@ Please see our [guide on what makes a good example](https://ebpf-go.dev/contribu
   * [tcp_close](tcprtt/) - Log RTT of IPv4 TCP connections using eBPF CO-RE helpers.
 * XDP - Attach a program to a network interface to process incoming packets.
   * [xdp](xdp/) - Print packet counts by IPv4 source address.
-  * [queue](queue/) - Print IPv4 Address and Unix Timestamp of each incoming packet.
 * Add your use case(s) here!
 
 ## How to run