feat(new sink): Azure Data Explorer Sink

[benmali]

Summary

This PR adds a new azure_data_explorer sink that delivers log events to Azure Data Explorer (Kusto) via queued ingestion. The sink supports Azure Entra ID (Azure AD) service principal authentication, configurable ingestion mapping, compression (gzip), and batching.

Vector configuration

[sinks.my_azure_data_explorer]
type = "azure_data_explorer"
inputs = ["my-source-id"]

# Required fields
ingestion_endpoint = "https://ingest-mycluster.eastus.kusto.windows.net"
database = "my_database"
table = "my_table"
tenant_id = "${AZURE_TENANT_ID}"
client_id = "${AZURE_CLIENT_ID}"
client_secret = "${AZURE_CLIENT_SECRET}"

# Optional fields
mapping_reference = "my_mapping"  # Optional ingestion mapping reference

# Batching (uses sensible defaults: 1000 events, 4MB, 30s timeout)
[sinks.my_azure_data_explorer.batch]
max_events = 1000
max_bytes = 4000000
timeout_secs = 30
compression = "gzip"

How did you test this PR?

• Added comprehensive unit tests covering:
  • Configuration parsing with required and optional fields
  • JSONL encoder functionality (multi-event, single-event, transformer filtering)
  • Mock-based integration test with simulated ADX management commands, blob upload, and queue enqueue operations
• Integration-style test validates component spec compliance using run_and_assert_sink_compliance
• Healthcheck validates credentials and endpoint reachability via .show version management command

Change Type

• Bug fix
• New feature
• Non-functional (chore, refactoring, docs)
• Performance

Is this a breaking change?

• Yes
• No

Does this PR include user facing changes?

• Yes. Please add a changelog fragment based on our guidelines.
• No. A maintainer will apply the no-changelog label to this PR.

References

N/A - New feature implementation

Notes

• This PR introduces changes to Vector dependencies (adds azure_identity crate in Cargo.lock)
• Will run make build-licenses to regenerate the license inventory if required by maintainers
• All new files follow Vector's standard architecture patterns (config, auth, encoder, service, sink, request_builder, resources)
• Implements queued ingestion flow: acquire ingestion resources → upload JSONL to blob storage → enqueue notification message

---

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[github-actions]

All contributors have signed the CLA ✍️ ✅
_{Posted by the CLA Assistant Lite bot.}

[benmali]

I have read the CLA Document and I hereby sign the CLA

[omers]

+1

[benmali]

Also relates to a request I made earlier #24435