test: updates E2E test network and image configuration

[universal-itengineer]

Description

This PR updates E2E test network and image configuration to make VM connectivity and migration scenarios more deterministic.

Key changes:

• Configure test ClusterNetwork to existing VLAN 4006 (cn-4006-for-e2e-test) instead of VLAN 1003 (cn-1003-for-e2e-test).
• Normalize image usage in E2E tests (switch most cases from perf image to stable Alpine UEFI image where needed).
• Fix object builders for Ubuntu resources (VI/CVI/VD) to use Ubuntu image URL instead of Alpine BIOS URL.
• Add dedicated constructors for Alpine BIOS/UEFI images in object helpers.
• Update additional network interfaces test:
  • move additional IPs to per-test-case params,
  • pass explicit IPs into connectivity checks,
  • adjust Alpine cloud-init service startup commands.

Why do we need it, and what problem does it solve?

• Additional network E2E scenarios require VMs to communicate over an existing cluster VLAN; without this VLAN setup, VM-to-VM ping on additional interfaces is unreliable or impossible.
• Image source mismatch in helper constructors (Ubuntu builders pointing to Alpine image) makes test intent inconsistent and can lead to unexpected behavior.
• Mixed usage of perf/stable images and rigid IP constants increases test fragility and makes migration/connectivity scenarios less reproducible.

What is the expected result?

Checklist

• The code is covered by unit tests.
• e2e tests passed.
• Documentation updated according to the changes.
• Changes were tested in the Kubernetes cluster manually.

Changelog entries