ADD IBAN FIELD TO STRUCTS AND UPDATE PARSING LOGIC

- Added `iban` field to the `IbanEx.Iban` struct to hold the full IBAN value. - Updated the parsing logic to populate
the new field. - Adjusted BBAN rules and tests for France and Brazil to reflect updated structures. - Improved error
handling and format validation routines.

lib/iban_ex/iban.ex

@@ -5,14 +5,21 @@ defmodule IbanEx.Iban do
   alias IbanEx.{Serialize}
 
   @type t :: %__MODULE__{
-    country_code: <<_::16>>,
-    check_digits: String.t(),
-    bank_code: String.t(),
-    branch_code: String.t() | nil,
-    national_check: String.t() | nil,
-    account_number: String.t()
-  }
-  defstruct country_code: "UA", check_digits: nil, bank_code: nil, branch_code: nil, national_check: nil, account_number: nil
+          iban: String.t(),
+          country_code: <<_::16>>,
+          check_digits: String.t(),
+          bank_code: String.t(),
+          branch_code: String.t() | nil,
+          national_check: String.t() | nil,
+          account_number: String.t()
+        }
+  defstruct iban: nil,
+            country_code: "UA",
+            check_digits: nil,
+            bank_code: nil,
+            branch_code: nil,
+            national_check: nil,
+            account_number: nil
 
   @spec to_map(IbanEx.Iban.t()) :: map()
   defdelegate to_map(iban), to: Serialize