pg_recvlogical: Honor source cluster file permissions for output files

pg_recvlogical: Honor source cluster file permissions for output files

Commit c37b3d08ca6 attempted to preserve group permissions on pg_recvlogical
output files when group access was enabled on the source cluster. However,
the output files were still created with a fixed S_IRUSR | S_IWUSR mode,
preventing group-read permissions from being applied.

This commit fixes the issue by creating output files with pg_file_create_mode
instead of a hard-coded mode. This allows pg_recvlogical to correctly preserve
group permissions from the source cluster.

Backpatch to all supported branches.

Author: Fujii Masao <masao.fujii@gmail.com>
Reviewed-by: Srinath Reddy Sadipiralla <srinath2133@gmail.com>
Discussion: https://postgr.es/m/CAHGQGwHhpizYzMo3nFP4GkNMueSNMY3QfC-gBN1VTXtuiANDvw@mail.gmail.com
Backpatch-through: 14