Declare the logger contract in the library instead of depending on @larvit/log

src/index.ts

@@ -38,6 +38,7 @@ export type { Dlr, Receipt } from './dlr.ts';
 export type { SendRespOptions, Sms, SmsInput } from './sms.ts';
 export type { ConcatInfo } from './udh.ts';
 export type { Result, VoidResult } from './result.ts';
+export type { SmppLog } from './log.ts';
 export type {
 	AuthenticateInput,
 	AuthenticateResult,