Read a delivery receipt's body as the octets that arrived (#81)

* Regression tests for a receipt body read under a data_coding it is not written in

* Read a delivery receipt's body as the octets that arrived, not by its data_coding

* Assert SMPPSim's UCS2 receipt body parses like every other segment's

* Record the receipt-body defect as fixed

* Retain a multipart segment's octets once, not twice

* Sort the new type import into its file's order

src/session.ts

@@ -1,7 +1,8 @@
 import type { ErrorName } from './defs/errors.ts';
 import type { MessageDlr } from './dlr-merger.ts';
 import type { ParamValue } from './defs/types.ts';
-import type { PduObject, PduObjectInput, PduRefusedError, TlvInput } from './pdu.ts';
+import type { PduObject, PduObjectInput, TlvInput } from './pdu.ts';
+import type { PduRefusedError } from './pdu-refusal.ts';
 import type { BindType, CloseOptions, ReconnectOptions, SendOptions, SessionEvents, SessionOptions } from './session-options.ts';
 import type { Result, VoidResult } from './result.ts';
 import type { SendSmsOptions, SendSmsResult } from './send-sms.ts';
@@ -18,7 +19,8 @@ import { leftOf } from './idle-waiters.ts';
 import { errorFrom } from './error-from.ts';
 import { optionalParamsMinVersion } from './defs/constants.ts';
 import { bindCarries, bindCommands, defaultSystemId, defaults } from './session-options.ts';
-import { isResp, objToPdu, pduReturn, refusalAnswer } from './pdu.ts';
+import { isResp, objToPdu, pduReturn } from './pdu.ts';
+import { refusalAnswer } from './pdu-refusal.ts';
 import { guardedLog } from './log.ts';
 import { submitSms, unsent } from './send-sms.ts';
 import { ConcatReference } from './udh.ts';