Strip dev_addr from ids in TTS exporter

[vlasebian]

Summary

References https://github.com/TheThingsIndustries/lorawan-stack-support/issues/1444#issuecomment-4342738364

Changes

• Strip dev_addr from ids on export for TTS source
• Fix the iterator for application mode for TTS source
• Add vendor directory to .gitignore

Testing

Before:

-> % go run ./cmd/ttn-lw-migrate --dry-run tts device --app-api-key $API_KEY --app-id adrian-test-lab --default-grpc-address tti.staging1.cloud.thethings.industries:8884 < devices.txt | jq '.ids'
{
  "device_id": "eui-0004a310001ab188",
  "application_ids": {
    "application_id": "adrian-test-lab"
  },
  "dev_eui": "0004A310001AB188",
  "join_eui": "70B3D57ED0000000",
  "dev_addr": "26002C07"
}

After:

-> % go run ./cmd/ttn-lw-migrate --dry-run tts device --app-api-key $API_KEY --app-id adrian-test-lab --default-grpc-address tti.staging1.cloud.thethings.industries:8884 < devices.txt | jq '.ids'
{
  "device_id": "eui-0004a310001ab188",
  "application_ids": {
    "application_id": "adrian-test-lab"
  },
  "dev_eui": "0004A310001AB188",
  "join_eui": "70B3D57ED0000000"
}

Regressions

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Notes for Reviewers

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Checklist

• Scope: The referenced issue is addressed, there are no unrelated changes.
• Documentation: Relevant documentation is added or updated.
• Changelog: Significant features, behavior changes, deprecations and fixes are added to CHANGELOG.md.

[johanstokking]

It looks good but it looks a bit weird to me.