feat: add trx.parseTransaction() and trx.parseTransactionLogs()

[0xyoshii]

Exposes TronWeb's existing hidden Interface class and adds high-level
trx.parseTransaction() / trx.parseTransactionLogs() methods, bringing
ethers.js equivalent transaction decoding to TronWeb with TRON-specific
address conversion.

The problem: TronWeb has an Interface class (adapted from ethers.js)
in src/utils/interface.ts with parseTransaction(), parseLog(), and
parseError() — but these are not exported, not documented, and only used
internally for function selector generation. Developers must manually extract
4-byte selectors, look up function signatures, call decodeParams() with
hand-specified types, and convert every address from hex to base58.

The solution:

• Export Interface, LogDescription, TransactionDescription, ErrorDescription
  as public API via tronWeb.utils.ethersUtils
• Add tronWeb.trx.parseTransaction(txIdOrData, abi?), parses smart contract
  calldata with auto ABI fetch and hex→base58 address conversion
• Add tronWeb.trx.parseTransactionLogs(txId, abi?), decodes event logs from
  transaction receipts
• Add ParsedTransaction and ParsedLog TypeScript types

Before (manual, ~15 lines)

const tx = await tronWeb.trx.getTransaction(txId);                                                                   
const data = tx.raw_data.contract[0].parameter.value.data;
const selector = data.slice(0, 8);                                                                                   
// manually look up function, specify types, decode, convert addresses...

After (one line)

const parsed = await tronWeb.trx.parseTransaction(txId);                                                             
// parsed.args.to is already in base58 format  

Test plan

• 14 unit tests for Interface class (parseTransaction, parseLog, parseError, roundtrip, selectors)
• 10 unit tests for trx.parseTransaction (TRC-20 transfer/approve, SunSwap V2 swap, addLiquidity, tuple params, error
  handling)
• 7,858 existing tests still passing (zero regressions)
• Manual verification on Nile testnet with real SunSwap transactions