Issue 51169 - UI - attr uniqueness - selecting empty subtree crashes cockpit
Description: When processing the typeAheadChange we need to check for a empty
string before treating the array like a list of objects.
Also updated README with contribution instructions
relates: https://pagure.io/389-ds-base/issue/51169
Reviewed by: spichugi(Thanks!)
Improve handling of typeAhead values.
In some cases its an array of strings, and in some cases it's array of objects