Add an init() that match the APIGatewayResponse (#91)

Add an `init()` to `FunctionURLResponse` to match the signature of
`APIGatewayv2Response`

### Motivation:

`APIGAtewayV2Response` and `FunctionURLResponse` share teh same
structure, although we provided two different signatures for the
initializers. This prevent writing common code to handle both responses.

### Modifications:

- add a new `init(0` that has the same signature as the init from
APIGatewayV2response
- make the current init as deprecated, we will remove it in a future
version bump

### Result:

Two init() functions on FunctionURLResponse

Author: sebsto

Sources/AWSLambdaEvents/FunctionURL.swift

@@ -92,6 +92,7 @@ public struct FunctionURLResponse: Codable, Sendable {
     public let cookies: [String]?
     public var isBase64Encoded: Bool?
 
+    @available(*, deprecated, message: "Use init(statusCode:headers:body:isBase64Encoded:cookies:) instead")
     public init(
         statusCode: HTTPResponse.Status,
         headers: HTTPHeaders? = nil,
@@ -105,4 +106,18 @@ public struct FunctionURLResponse: Codable, Sendable {
         self.cookies = cookies
         self.isBase64Encoded = isBase64Encoded
     }
+
+    public init(
+        statusCode: HTTPResponse.Status,
+        headers: HTTPHeaders? = nil,
+        body: String? = nil,
+        isBase64Encoded: Bool? = nil,
+        cookies: [String]? = nil
+    ) {
+        self.statusCode = statusCode
+        self.headers = headers
+        self.body = body
+        self.cookies = cookies
+        self.isBase64Encoded = isBase64Encoded
+    }
 }