[Studio] Supplement full-module i18n translation keys and provide useLanguage compatibility hook

[zhaohai666]

Description
The current Studio frontend i18n translation resources are incomplete, and there is no compatible useLanguage hook for migrating components from the oldfrontend-new repository. It causes missing text display and extra adaptation work during page migration.
To unify internationalization specifications and smooth the migration progress, we need to supplement full business module translation keys and add a compatible language hook alias.
Objective

• Provide useLanguage hook alias compatible with old frontend components
• Supplement missing i18n translation keys for all core business modules
• Unify all translation keys to dot-separated namespace specification
• Fully support subsequent page migration from frontend-new
  Expected Changes

1. Language Context Compatibility

• Add useLanguage as an alias of useLang in LangContext.tsx
• No breaking changes, fully compatible with existing code

2. Full Module Translation Supplement
   Expand translation resources and add 400+ standardized dot-namespace translation keys covering the full business scope:

• login.* Login page
• ops.* Operation management page
• topic.* Topic management
• group.* Consumer group management
• message.* Message query
• dlq.* Dead letter queue
• trace.* Message trace
• broker.* Broker detail
• proxy.* Proxy cluster management
• ssl.* SSL configuration
• ns.* Namespace management
• alert.* Alert management
• liteTopic.* LiteTopic management
• producer.* Producer related
• common.* Universal common text keys
  Specification
• All translation keys follow dot-separated namespace naming standard
• Migrate and convert legacy uppercase underscore keys from frontend-new to new standard
• Ensure no duplicate or invalid translation entries
  Acceptance Criteria
• useLanguage and useLang can be used interchangeably
• All newly added translation items take effect correctly
• No missing text for migrated business pages
• All keys comply with unified namespace specification
  Related Branch
  [studio][i18n] Extend translation keys & add useLanguage compatible alias in LangContext #433