Correct help for Typeahead Datasource Controls without functions
Summary:
Do not display an empty table of Functions and irrelevant instructions when the Typeahead Datasource Control does not support any typeahead functions in order to avoid confusion.
Closes T16169
Test Plan:
* Go to http://phorge.localhost/typeahead/help/PhabricatorPeopleUserFunctionDatasource/ and still see functions listed as expected (no change)
* Go to http://phorge.localhost/typeahead/help/ConpherenceThreadDatasource/ or http://phorge.localhost/typeahead/help/PhabricatorSearchDatasource/ and see much less text and instead information that this control does not support typeahead functions.
Reviewers: O1 Blessed Committers, mainframe98
Reviewed By: O1 Blessed Committers, mainframe98
Subscribers: tobiaswiese, valerio.bozzolan, Matthew, Cigaryno
Maniphest Tasks: T16169
Differential Revision: https://we.phorge.it/D26176