One of the reasons why #16447 was needed and why #16268 was needed in
the first place was because it appears that editing ldap configuration
doesn't get tested.
This PR therefore adds a basic test that will run the edit pipeline.
In doing so it's now clear that #16447 and #16268 aren't actually
solving #16252. It turns out that what actually happens is that is that
the bytes are actually double encoded.
This PR now changes the json unmarshal wrapper to handle this double
encode.
Fix#16252
Signed-off-by: Andrew Thornton <art27@cantab.net>
Co-authored-by: 6543 <6543@obermui.de>