feat: support message fills on Solana

[bmzig]

Depends on across-protocol/sdk#1270. Must also have a Solana JITO RPC endpoint.

A message fill which can fit in a single transaction:

2026-01-09 12:20:04 [info]: {
  "at": "SvmFillerClient#executeTxnQueue",
  "message": "Filled v3 deposit on SVM 🚀",
  "mrkdwn": "Relayed depositId 4129014 from Arbitrum One to Solana of 1.30 USDC and output 1.00 USDC, with depositor <https://arbiscan.io/address/0x9A8f92a830A5cB89a3816e3D267CB7791c16b04D | 0x9A8..6b04D>. Realized LP fee: 0.000%, total user fee: 23.07%. Gas price used in profit calc: 0.00001852 Gwei. Relayer repayment: Arbitrum One.",
  "signatures": [
    "26gvyZt6ekqXAugKgEvPu5ogRmPBPfjVDqpnFYmZzJ1hYcpY3DNDKDbbtB1bCjE6Km7Ehu8C1eyPMHkuLFaCFmZM"
  ],
  "explorer": "<https://solscan.io/tx/26gvyZt6ekqXAugKgEvPu5ogRmPBPfjVDqpnFYmZzJ1hYcpY3DNDKDbbtB1bCjE6Km7Ehu8C1eyPMHkuLFaCFmZM | 26gvy..CFmZM>",
}

A message fill which requires multiple separate transactions:

2026-01-09 12:32:17 [info]: {
  "at": "SvmFillerClient#executeTxnQueue",
  "message": "Filled v3 deposit on SVM 🚀",
  "mrkdwn": "Relayed depositId 4129040 from Arbitrum One to Solana of 1.30 USDC and output 1.00 USDC, with depositor <https://arbiscan.io/address/0x9A8f92a830A5cB89a3816e3D267CB7791c16b04D | 0x9A8..6b04D>. Realized LP fee: 0.000%, total user fee: 23.07%. Gas price used in profit calc: 0.000008661 Gwei. Relayer repayment: Arbitrum One.",
  "signatures": [
    "4Sne9bE16QMppYbsx9EY7bA4PD5udPcPHqn94x12tGVZ3W3W7smECVJooisWJToxAXefmNrfB7P7keZTH6A92F7q",
    "2mjVZADJhmHx6DpfdDeSZk5iWwaDge7CEwr9ZdDwHxuLZqt77FS4zv4NqwoxBvzPGeMsw3CSnGPEb8PA17gVTBNp",
    "5f5vVB7RCq3r2QKuRkMp8vwwiKDKBvUFUcUvLg8ZEL3nZXHB23yHHDVaxV67HDCa8viLdgUUa2cumUnKb7cbAWY6",
    "47FNt4uevpKNdoGcuhaxy2c6Qy1JYAk4YMea8ngA3WgKpWM4ddMngfB6P7iLKavcwoJsZjNghbhV2b2HhhhsV7HK",
    "2fb1CG9LmBSga8YshNWpwEvP3yCkJ4LM7cEKKLDHCryerVrDxX6Esw8Q6ZWeatrVXcCVamojuKVdaY16TXJ7p4pV"
  ],
  "explorer": "<https://solscan.io/tx/2fb1CG9LmBSga8YshNWpwEvP3yCkJ4LM7cEKKLDHCryerVrDxX6Esw8Q6ZWeatrVXcCVamojuKVdaY16TXJ7p4pV | 2fb1C..7p4pV>",
  "run-identifier": "42adcd99-3c29-47d1-a199-4a56c349e5d7"
}