Add native Solana balance and transfer support

- SolanaTransaction: hand-rolled compact-u16/legacy-Message/signed-tx
  wire-format primitives, cross-validated byte-for-byte against the
  solders Python library's own serialization of an identical System
  Program transfer message.
- SolanaApi: JSON-RPC client (getBalance/getLatestBlockhash/
  getFeeForMessage/sendTransaction) over a single POST endpoint, unlike
  Tron/Bitcoin's path-per-resource REST style.
- SolanaNativeAssetBalance: getBalance polling, same design as Bitcoin's
  mempool.space polling (no push/subscription mechanism available).
- RealSolanaTransactionService: builds a single-instruction transfer
  message, signs it raw via the existing Ed25519 signer dispatch
  (skipMessageHashing - Solana signs the message directly, no external
  hashing), broadcasts via sendTransaction. Fee is Solana's actual
  getFeeForMessage answer, not a client-side estimate.
- TransactionExecution.Solana(hash) variant; wired into AssetsModule via
  a new SolanaAssetsModule, following the Bitcoin/Tron precedent exactly.

feature-wallet-api/src/main/java/io/novafoundation/nova/feature_wallet_api/data/network/blockhain/assets/tranfers/TransactionExecution.kt

@@ -12,4 +12,6 @@ sealed interface TransactionExecution {
     class Bitcoin(val hash: String) : TransactionExecution
 
     class Tron(val hash: String) : TransactionExecution
+
+    class Solana(val hash: String) : TransactionExecution
 }