Add fiftyone.pipeline.translation base engine

[Jamesr51d]

Background

51Degrees on-premise IP Intelligence returns country information as weighted
lists of ISO country codes. Turning those into localized, ordered country
names (Runbook 2) needs a generic translation flow element, mirroring the .NET
FiftyOne.Pipeline.Translation package. pipeline-node had no translation
element for this.

Objectives

• Add a reusable translation flow element that the ip-intelligence-node country
  engines build on.
• Reproduce the .NET base behaviour: evidence precedence, locale resolution
  with the English short-circuit, weighted-list translation that preserves the
  weights, and the Original missing-translation behaviour.

Key Decisions

• New standalone package fiftyone.pipeline.translation, mirroring the .NET
  separate base package, rather than inlining the logic into the IP engines.
• The base extends the core FlowElement (not an engine), matching .NET where
  TranslationEngineBase extends FlowElementBase. It depends only on
  fiftyone.pipeline.core and js-yaml.
• The translator duck-types AspectPropertyValue and the weighted value shape
  ({ value, weight, rawWeight }) rather than relying on instanceof, so it
  works regardless of which copy of core produced the value.
• YAML sources are parsed inside the base with js-yaml, keeping the consumer
  builders thin and faithful to the .NET design.

Changes

• New package fiftyone.pipeline.translation:
  • translationEngine.js: the flow element. Reads a source element, resolves
    the language (fixed or from query.translation, query.accept-language,
    header.accept-language), translates the configured properties.
  • translator.js: string, string-list, weighted-list and
    AspectPropertyValue translation with weights preserved.
  • languages.js: Accept-Language parsing and locale resolution with the
    English base-language short-circuit and the two-letter fallback.
  • translationData.js, missingTranslationBehavior.js, index.js,
    readme.md, tests/base.test.js.
• Added the package to ci/build-package.ps1, ci/build-project.ps1 and
  ci/update-packages.ps1.

Testing

• npm test (jest) in fiftyone.pipeline.translation: 8 tests pass, covering
  Accept-Language ordering, exact and two-letter locale resolution, the English
  short-circuit, preferred-before-lower-priority resolution, weighted-list
  weight preservation, the Original miss behaviour and no-value message
  preservation.

Notes

• This is the base for the companion ip-intelligence-node PR. The country
  engines there depend on this package.
• No new data files are shipped.