Native support for storing bind_pw in hiera; ldap_options is now more flexible.

[sandynomad]

There was no intrinsic way to store an encrypted bind password in heira, so added '$postfix::ldap_bind_pw'.

Converted '$postfix::ldap_options' to be optional or a string or an array of strings.

Modified the ldap-aliases.cf template so that ldap_options can be optional / a string / an array of strings, and then rendered in alphabetical order.

[smortex]

@sandynomad :wave:

This look good, if you are still interested in getting this merged, can you please rebase your changes on top of master?

Rebasing guide

From your work branch, assuming the remote of voxpupuli is named `origin`: ``` git fetch origin # Download the latest code we have here git rebase origin/master # Move your commits on top of the main branch # Fix conflicts, see `git status` for what to do next. git push -f # Send the changes (-f is required because we re-wrote history) ```

This PR seems to predate CI and has some conflicts, this would help us move along.

Thanks!