Resolves: #1859252
- libsubid: creation and nsswitch support
- Creation of subid and subid-devel subpackages
- man: mention NSS in new[ug]idmap manpages
- libsubid: move development header to shadow folder
- libsubid: don't print error messages on stderr by default
- libsubid: libsubid_init return false if out of memory
- useradd: fix SUB_UID_COUNT=0
- libsubid: don't return owner in list_owner_ranges API call
- libsubid: libsubid_init don't print messages on error
- libsubid: fix newusers when nss provides subids
- man: clarify subid delegation
- libsubid: make shadow_logfd not extern
- login.defs: include HMAC_CRYPTO_ALGO key
