refactor: consolidate getAccountMetadata into @transaction/lib/metadata

- Create new metadata.ts in packages/transaction with shared functions
- Add MetadataProps interface to app-types.ts
- Update all wallet pages to import from @transaction/lib/metadata
- Remove re-exports from wallet/lib/get-translations.ts
- Delete blog/lib/get-metadata.ts (was only re-exporting)

Functions consolidated:
- getAccountMetadata
- getCommunityMetadata
- MetadataProps type