[MANOPD-77444] Fix check_iaas for ipv6 environment

[akor0421]

Description

Check_iaas procedure fails on network.pod_subnet_connectivity/network.service_subnet_connectivity in the ipv6 environment.

Fixes # (issue)
MANOPD-77444

Solution

1. The number of possible addresses in the ipv6 network exceeds the maximum allowed value for the list in python. Added a limit for the list of 1 million addresses.
2. For the 'ip' command, the format of the entry "ip a add <ip>/<net_mask>" is not applicable for ipv6 addresses. Fixed to "ip a add <ip>/<prefixlength>".
3. simple_tcp_listener.py script did not work for ipv6 addresses. Added an argument that allows to select the ip protocol version.

How to apply

none

Test Cases

Run check_iaas procedure against ipv4 and ipv6 clusters.
In both cases the result should contain

Checklist

• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• Integration CI passed
• Unit tests. If Yes list of new/changed tests with brief description
• There is no merge conflicts

Unit tests

[alku89]

tested on qa env