Add save/restore in CLI help message and control restore parameters
The actions save and restore are not present in CLI help.
Other improvement, check that a file is provided to restore, else we get this:
# /usr/share/lemonldap-ng/bin/lemonldap-ng-cli restore
Use of uninitialized value $file in string eq at /usr/share/perl5/Lemonldap/NG/Manager/Cli.pm line 208, <FILE> line 1.
Use of uninitialized value $file in open at /usr/share/perl5/Lemonldap/NG/Manager/Cli.pm line 212, <FILE> line 1.
readline() on closed filehandle $f at /usr/share/perl5/Lemonldap/NG/Manager/Cli.pm line 213.
[Sun Jun 30 17:32:27 2019] [LLNG:2660] [warn] [anonymous] malformed JSON string, neither tag, array, object, number, string or atom, at character offset 0 (before "(end of string)") at /usr/share/perl5/JSON.pm line 171.
Bad file descriptor
$VAR1 = [
400,
[
'Content-Type',
'application/json; charset=utf-8'
],
[
'{"error":"malformed JSON string, neither tag, array, object, number, string or atom, at character offset 0 (before \\"(end of string)\\") at /usr/share/perl5/JSON.pm line 171.\\nBad file descriptor"}'
]
];