locales: dehardcode quest strings and normalize translation keys

[MikelCalvo]

Summary

This PR performs a quest localization cleanup by moving remaining player-facing quest strings out of quest scripts and into the shared translate*.lua tables.

Besides the de-hardcoding pass itself, it also fixes a small set of inconsistent or missing active gameforge.* references that were still present in quest scripts.

• replaced remaining hardcoded quest UI/dialogue/reward strings with gameforge.* keys
• reused existing translation keys whenever possible
• added missing keys to translate.lua and all translate_<lang>.lua files where needed
• normalized a few inconsistent key references in active quests
• added the missing pricing_lv3 translation namespace across the translation tables
• kept quest logic unchanged; the scope is localization/consistency only

Why this matters

This change makes future translation work much easier and safer.

By centralizing player-facing text in translate*.lua instead of keeping it embedded in quest scripts:

• translators can update text without touching quest logic
• adding or improving locales becomes a translation-table task instead of a quest-by-quest code audit
• shared wording and formatting can be reused consistently across quests
• future localization passes become more mechanical and less error-prone
• the risk of introducing gameplay regressions while editing text is reduced significantly

In short, this PR does not just clean up current quest strings — it also improves the structure for future localization work.

Validation

• checked active quest gameforge.* references against translate.lua
• fixed inconsistent or missing active references
• verified there are no duplicate translation keys in translate*.lua
• validated all touched translation files with luac -p