Allow Field to specify its own data

src/types.ts

@@ -120,6 +120,7 @@ export interface Segment {
 export interface Field {
   type: FieldType;
   name: string;
+  data?: ArrayBuffer; // Optional raw data for the field (if needed for parsing / serialization)
   value?: unknown; // Optional value for the field (used for serialization or as a default value)
   bits?: BitField[]; // Optional array of bit field definitions (for BITS type)
   length?: number; // Optional length for array types (e.g., BYTES, WORDS)