(BugID: 68678) Fix LookupUser returning does not exist error

LookupUser can return a user does not exist error on first load
if the user has never been previously loaded on the local wiki.
Adding message documentation
(BugID: 68678) Fix EditAccount returning does not exist error

EditAccount can return a user does not exist error on first load
if the user has never been previously loaded on the local wiki.
Merge branch 'bugid-68678' into dev