feat(sources): multicast udp socket support

[jorgehermo9]

Closes #5732

This PR is still in draft. I have a few pending TODOs and also missing tests to propertly check this. Although, the happy path is working.

In order to test this, use this vector config:

[sources.multicast_udp]
type = "socket"
mode = "udp"
address = "0.0.0.0:4242"
multicast_groups = ["224.0.0.2"]


[sinks.console]
type = "console"
inputs = ["multicast_udp"]
encoding.codec = "json"

and with this command

echo "hello" | nc 224.0.0.2 4242 -u

you can see logs in vector.

I would like to receive some feedback about how the configuration of this setting should look like.

Also, note that IPv6 is not supported. We can work on that, but maybe it is not worth it if no one request that.

@nomalord take a look into this please, It would be great if you can build the binary from this branch and test if it works in your systems.

@dalesample as you were the first requester of this I also ping you, just in case (although this issue was created 4 years ago)

[jorgehermo9]

Inspired from the SocketAddr implementation a few lines above

[nomalord]

This looks awesome🤯
As it's new years I won't be able to check our usecase until Thursday...
I will say though, that this looks like it answers our usecase exactly🙏🙏🙏🙏🙏🙏