[Feat] Implement an ATSSS demo script

[oliveiraleo]

Is your feature request related to a problem? Please describe.

No

Describe the solution you'd like

A script that uses the virtual network interfaces (uesimtun0, etc) from each one of the UEs to implement the ATSSS technique

Describe alternatives you've considered

N/A

Additional context

Implementing a working prototype version may involve using ping and MPTCP.

For more detailed information, see 3GPP TS 24.193 version 18.7.0 Release 18 and 3GPP TS 23.501 version 18.7.0 Release 18

Contribution possibility

Do you have the possibility of contributing code with your request (e.g. with a PR)? (Choose one of the options below and delete the others)

[x] Yes, I know where to start but I don't have time to contribute a PR