pg_waldump: add test for coverage

When Who What
2022-09-30 21:59:01 Peter Eisentraut (petere) Closed in commitfest 2022-09 with status: Returned with feedback
2022-09-24 17:54:16 Tom Lane (tgl) Changed topic to Testing
2022-09-06 05:58:23 Peter Eisentraut (petere) New status: Waiting on Author
2022-08-24 19:00:40 Peter Eisentraut (petere) Added petere as reviewer
2022-08-23 01:51:17 DongWook Lee (dongwooklee) Changed authors to DongWook Lee (dongwooklee)
2022-08-23 01:51:05 DongWook Lee (dongwooklee) Attached mail thread CAAcByaKM7zyJSDkPWv6_+apupY4fXXM3q3SRXas9MMNVPUGcsQ@mail.gmail.com
2022-08-23 01:51:05 DongWook Lee (dongwooklee) Created patch record