Improve Relink UI and add People Picker (CFM-125)

[arlen]

No description provided.

[benno]

Arlen's original comments (from Slack):

1. To get this to work, I had to unlock the field in the view. I could not determine how to get around that - possibly I haven’t correctly made the field output look exactly like it would be from Cake. (See: https://github.internet2.edu/COmanage/registry/pull/316/files#diff-19b82a055c6b965b53fd7cca04e59480542c74f9c6f79a63af9b00528ab1c01e )
2. The people picker (working against the API) does not appear to be finding Person information as I expect it to do. I re-linked an external Identity from one person to another in my set, but when I try to link it back, the search only finds the new person. It’s as if the ApiV2Controller::pick() action only is finding the underlying MVEAs from the External Identities…
3. I left the current implementation of the people picker mostly alone - so I kept the new StringUtilities function. The autocomplete widget from PrimeVue can be set up within a javascript context to return a specific field - but I did not pursue that yet (because the first two items above need to be examined more). I also did not change the Manager and Sponsor pickers to use the new StringUtilities function (yet).

[arlen]

Simplified and rebased against the latest develop. The original comment (above) from Slack is largely no longer accurate. (1) is outdated - there is no unlocking. (2) Is not a correct description, but there are some peculiarities when searching with the picker (I'll create a different ticket as this gets tracked down), and (3) is also outdated. The new string utilities function is not needed (and has been removed from this PR).