Add RPC getAccountInfo method

Sources/SolanaRPC/methods/getAccountInfo.swift

@@ -0,0 +1,74 @@
+import Foundation
+import SolanaTransactions
+import SwiftBorsh
+
+public enum AccountData: Codable {
+    case string(String)
+    case encoded([String])
+    case object([String: String])
+
+    public init(from decoder: Decoder) throws {
+        let container = try decoder.singleValueContainer()
+        if let stringValue = try? container.decode(String.self) {
+            self = .string(stringValue)
+        } else if let arrayValue = try? container.decode([String].self) {
+            self = .encoded(arrayValue)
+        } else if let objectValue = try? container.decode([String: String].self) {
+            self = .object(objectValue)
+        } else {
+            throw DecodingError.dataCorruptedError(
+                in: container,
+                debugDescription: "Invalid AccountData format"
+            )
+        }
+    }
+
+    public func encode(to encoder: Encoder) throws {
+        var container = encoder.singleValueContainer()
+        switch self {
+        case .string(let v): try container.encode(v)
+        case .encoded(let v): try container.encode(v)
+        case .object(let v): try container.encode(v)
+        }
+    }
+}
+
+extension SolanaRPCClient {
+    public struct GetAccountInfoConfiguration: Encodable {
+        let commitment: Commitment?
+        let encoding: TransactionEncoding?
+        let dataSlice: DataSlice?
+        let minContextSlot: UInt64?
+    }
+
+    public struct DataSlice: Encodable {
+        let offset: UInt64
+        let length: UInt64
+    }
+
+    public struct GetAccountInfoResponse: Decodable {
+        let data: AccountData
+        let executable: Bool
+        let lamports: UInt64
+        let owner: String
+        let rentEpoch: UInt64
+        let space: UInt64
+    }
+
+    /// https://solana.com/docs/rpc/http/getaccountinfo
+    public func getAccountInfo(
+        account: PublicKey,
+        configuration: GetAccountInfoConfiguration? = nil
+    ) async throws(RPCError) -> GetAccountInfoResponse {
+        var params: [Encodable] = [account]
+        if let configuration {
+            params.append(configuration)
+        }
+
+        return try await fetch(
+            method: "getAccountInfo",
+            params: params,
+            into: RPCResponseResult<GetAccountInfoResponse>.self
+        ).value
+    }
+}