The various LDAP check Rake tasks have long supported a SANITIZE
environment variable. When present, identifiable information is
obscured such as user names and project/group names. Until now,
the LDAP check did not honor this. Now it will only say how many
users were found. This should at least give the indication that
the LDAP configuration found something, but will not leak what
it is. Resolves#56131
It was previously possible for invalid credential errors to go unnoticed
in this task. Users would believe everything was configured correctly and
then sign in would fail with 'invalid credentials'. This adds a specific
bind check, plus catches errors connecting to the server. Also, specs :)
