Summary:
Fixing YB_TODOs in the `pg_dump.c`.
`fatal()` function calls were replaced by `pg_fatal()` calls.
Jira: DB-14524

Test Plan: Jenkins

Reviewers: mihnea, yguan

Reviewed By: yguan

Subscribers: smishra, yql

Differential Revision: https://phorge.dev.yugabyte.com/D40580