T5942: Make failover support dhcp-interface

[hedrok]

Make failover support dhcp-interface

• Refactor XML a little: move common dhcp-interface properties to separate include file
• Add failover support for dhcp-interface
• Add test for DHCP in failover protocol
• Change vyos.template.get_dhcp_router to use '*.lease' file instead of '.leases' file - in 'leases' there can be several last leases and current one may not be the first one in file

Command sample:

    set protocols failover route 203.0.113.0/24 dhcp-interface eth1 interface eth1
    set protocols failover route 203.0.113.0/24 dhcp-interface eth1 metric 30
    set protocols failover route 203.0.113.0/24 dhcp-interface eth1 check target 10.25.0.47
    set protocols failover route 203.0.113.0/24 dhcp-interface eth1 check timeout 1

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/T5942

Related PR(s)

How to test / Smoketest result

I've added test case:

$ /usr/libexec/vyos/tests/smoke/cli/test_protocols_failover.py
test_01_basic (__main__.TestProtocolsFailover.test_01_basic) ... ok
test_02_vrf (__main__.TestProtocolsFailover.test_02_vrf) ... ok
test_03_config (__main__.TestProtocolsFailover.test_03_config) ... ok
test_04_dhcp (__main__.TestProtocolsFailover.test_04_dhcp) ... ok

-->

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 (https://docs.vyos.io/en/latest/configuration/protocols/failover.html)
• I have updated the documentation accordingly

[github-actions]

👍
No issues in PR Title / Commit Title

[github-actions]

CI integration ❌ failed!

Details

CI logs

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