interface: T4627: support setting of IPv6 Interface Identifier(Token)

[symysak]

Change summary

Support setting of IPv6 Interface Identifier (a.k.a Token) for IPv6 autoconfig(SLAAC).

https://docs.redhat.com/en/documentation/red_hat_enterprise_linux/6/html/deployment_guide/s2-configuring_ipv6_tokenized_interface_identifiers#s2-Configuring_IPv6_Tokenized_Interface_Identifiers

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Code style update (formatting, renaming)
• Refactoring (no functional changes)
• Migration from an old Vyatta component to vyos-1x, please link to related PR inside obsoleted component
• Other (please describe):

Related Task(s)

https://vyos.dev/T4627

Related PR(s)

How to test / Smoketest result

1. Connect eth0 to Router, that is enabled IPv6 RA.
2. Configure as follows

interfaces {
    ethernet eth0 {
        ipv6 {
            address {
                autoconf
                interface-identifier 0000:0000:cafe:0001
            }
        }
    }
}

3. Check(We can find a ipv6 address ::cafe:1/64)

vyos@vyos:~$ show int
Codes: S - State, L - Link, u - Up, D - Down, A - Admin Down
Interface    IP Address                     MAC                VRF        MTU  S/L    Description
-----------  -----------------------------  -----------------  -------  -----  -----  -------------
eth0           <my prefix>::cafe:1/64  <my mac>  default   1500  u/u

Checklist:

• I have read the CONTRIBUTING document
• I have linked this PR to one or more Phabricator Task(s)
• I have run the components SMOKETESTS if applicable
• My commit headlines contain a valid Task id
• My change requires a change to the documentation
• I have updated the documentation accordingly

[github-actions]

👍
No issues in PR Title / Commit Title

[symysak]

I am Yoshiaki Suyama
This PR is the first contribution to VyOS, so it may contain some mistakes. Sorry.

The lint check seems to have failed except for my changes. Is there anyone who can fix this?

[github-actions]

CI integration 👍 passed!

Details

CI logs

• CLI Smoketests (no interfaces) 👍 passed
• CLI Smoketests (interfaces only) 👍 passed
• Config tests 👍 passed
• RAID1 tests 👍 passed
• TPM tests 👍 passed