Udhcp probe

[muhamadazmy]

This PR changes the way probing for interfaces is done. Instead of starting udhcp and leave it running then check if the interface got an IP. Instead what we do is that we run udhcpc with a different script that just prints the lease information received by udhcpc as a json object.

Udhcpc then is started with few extra flags that makes it exit the moment is received or times out.

This make it faster and much better to debug what happens if a node did not receive a dhcp lease.

Note: The script appears in 2 locations because:

• Old images that is already booted needs a copy of that script so updated networkd can work normally (since probe code now uses it)
• New images need to include this script as well (0-initrafms) hence script is also included in bootstrap that is already merged to main.