pgsql: Move basebackup code to new directory src/backend/backup

Move basebackup code to new directory src/backend/backup

Reviewed by David Steele and Justin Pryzby

Discussion: http://postgr.es/m/CA+TgmoafqboATDSoXHz8VLrSwK_MDhjthK4hEpYjqf9_1Fmczw%40mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/a8c012869763c711abc9085f54b2a100b60a85fa

Modified Files
--------------
contrib/basebackup_to_shell/basebackup_to_shell.c | 2 +-
src/backend/Makefile | 3 ++-
src/backend/access/transam/xlog.c | 2 +-
src/backend/access/transam/xlogrecovery.c | 2 +-
src/backend/backup/Makefile | 30 ++++++++++++++++++++++
.../{replication => backup}/backup_manifest.c | 6 ++---
src/backend/{replication => backup}/basebackup.c | 12 ++++-----
.../{replication => backup}/basebackup_copy.c | 6 ++---
.../{replication => backup}/basebackup_gzip.c | 4 +--
.../{replication => backup}/basebackup_lz4.c | 4 +--
.../{replication => backup}/basebackup_progress.c | 6 ++---
.../{replication => backup}/basebackup_server.c | 6 ++---
.../{replication => backup}/basebackup_sink.c | 4 +--
.../{replication => backup}/basebackup_target.c | 4 +--
.../{replication => backup}/basebackup_throttle.c | 4 +--
.../{replication => backup}/basebackup_zstd.c | 4 +--
src/backend/replication/Makefile | 11 --------
src/backend/replication/walsender.c | 2 +-
src/bin/pg_basebackup/pg_basebackup.c | 2 +-
.../{replication => backup}/backup_manifest.h | 4 +--
src/include/{replication => backup}/basebackup.h | 2 +-
.../{replication => backup}/basebackup_sink.h | 2 +-
.../{replication => backup}/basebackup_target.h | 4 +--
23 files changed, 73 insertions(+), 53 deletions(-)