[CHAOSPLT-259] Add percentage-based IP selection for network disruptions

[aymericDD]

What does this PR do?

• Adds new functionality
• Alters existing functionality
• Fixes a bug
• Improves documentation or testing

Please briefly describe your changes as well as the motivation behind them:

This PR implements percentage-based IP selection for network disruptions, enabling users to target only a specific percentage (1-100%) of resolved IPs for both hosts and services.

Key Features:

• Uses SHA-256 consistent hashing for deterministic IP selection
• Ensures the same IP subset is selected across all chaos pods within a single disruption run using Kubernetes Disruption UID as seed
• Supports both hosts and services
• Includes validation for percentage range (1-100)

Motivation:

• Gradual Impact: Start with smaller disruption percentages to minimize blast radius (e.g., disrupt 10% of IPs first, then increase)
• A/B Testing: Compare behavior between disrupted and non-disrupted IP subsets
• Load Balancing Scenarios: Test how applications handle partial endpoint failures in load-balanced services
• Consistency: Predictable behavior across distributed chaos pods using the same seed within a disruption run

Code Quality Checklist

• The documentation is up to date.
• My code is sufficiently commented and passes continuous integration checks.
• I have signed my commit (see Contributing Docs).

Testing

• I leveraged continuous integration testing
  • by depending on existing unit tests or end-to-end tests.
  • by adding new unit tests or end-to-end tests.
• I manually tested the following steps:
  - Created example manifest (network_dns_resolver_control.yaml) demonstrating percentage-based selection
  - Tested with 50% host disruption and 30% service disruption scenarios
  - Verified consistency: same IPs selected across multiple chaos pods within same disruption
  - Verified variability: different IPs selected when disruption is recreated (new Disruption UID)
  - Validated backward compatibility: existing disruptions work without modifications (defaults to 100%)
  - [x] locally.
  - [ ] as a canary deployment to a cluster.

Resolve issue: #843

[aymericDD]

Warning

This pull request is not mergeable via GitHub because a downstack PR is open. Once all requirements are satisfied, merge this PR as a stack on Graphite.
Learn more

• [CHAOSPLT-1364] Fix cloud disruption hosts only injected in first chaos pod #1012
• [CHAOSPLT-259] Add percentage-based IP selection for network disruptions  #1011 👈 (View in Graphite)
• [CHAOSPLT-1360] Add DNS resolv.conf path customization for network disruptions #1010
• [CHAOSPLT-1359] Add DNS resolver control #1009
• main

This stack of pull requests is managed by Graphite. Learn more about stacking.

[datadog-official]

✅ Tests

🎉 All green!

❄️ No new flaky tests detected
🧪 All tests passed

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