Add support for multiple user DNs

[iamroddo]

[RangerRick]

@iamroddo Hey, I'm going to be helping to take over maintainership of this helm chart and I just wanted to check in on this PR. It looks reasonably simple, but the patch ends up being pretty huge because of a bunch of mostly-unrelated formatting changes.

Are you still interested in contributing this? If so, do you mind rebasing it and giving it another pass with a smaller footprint? Also, it appears that everywhere else in the patch you use userSearchDnList to specify the list of DNs, but values.yaml got updated to just specify an example of userSearch.