Improvements to namespaces in UI

increase namespace tab width to allow upto 24 characters, but this should be dynamic, based on the length of the current namespace (there shouldn't be extra white space for smaller namespaces)

limit new namespace length to 24 characters in administration tab (Pending change to administration) - the experience should be the same as setting new adapter name (in terms of msg, countdown to characters etc, so it is consistent)

for namespaces that exceed 24 characters (created via CLI, curl etc), display 21 characters with ... (ellipsis), along with tooltip