Fix mobile app errors: string imports, useSwap hooks, isEmptyString, navigation, and translation keys
- Fix useSwap import paths from SwapProvider to useSwap.ts - Fix isEmptyString import from utils/utils to utils/string - Fix string property access patterns (portfolio.tokens, portfolio.nfts, etc.) - Add missing translation keys for direction messages - Fix bottom tab navigation icons - Fix navigation paths and component imports - Add missing string functions (tokens, nfts, tokensAvailable) - Fix TypeScript errors for supportedCurrencies export - Update translation message IDs to match JSON keys - Fix component import paths (Tab/Tabs, Copiable, etc.) - Add safety checks for undefined components and properties