[biodranik]

Generating a regional locale mutates the parsed definitions, so an alias can change from Pedestrian Bridge to Bridge when its reference appears first. Plural aliases also lose their forms, and Gettext export can crash when developer text is inherited.

• Give duplicated definitions independent translation, plural and tag collections while keeping reference objects shared. Generation becomes repeatable and independent of definition order.
• Resolve plural forms through references and choose the output resource type for the requested language. Explicit singular and empty values override inherited plurals. Preserve every resolved fallback form and keep empty plural output skippable.
• Reuse reference lookup for Gettext developer text, including the developer-language option. Reject dangling references and cycles during reading and explicit validation.
• Compute fallback languages once per output, use a constant script mapping, and support three-letter base languages. This keeps the simplification at the processor boundary and leaves [fallback] Resolve language priority through references #33's language-priority lookup change separate.

Based directly on organicmaps; contains only Ruby changes. Related review: #33. This PR can be reviewed independently of #33.

Validation:

• Ruby 4.0: 235 tests, 614 assertions, one existing skip; no failures or errors.
• All changed Ruby files pass the Ruby 2.6 syntax check.
• Ruby and Python PR [python] Preserve inherited localization data and resource types #34 agree on 146,685 real translation/plural results; source models remain unchanged.
• Isolated fallback-hoisting benchmark: approximately 5% less processor time on the real data.
• Combined with [fallback] Resolve language priority through references #33 and the other fix PR: clean automatic merge, 182 Python tests and 238 Ruby tests (one existing skip), Ruff clean.

Implementation and validation assisted by Codex.