SQLite - Add (function) editor to node

[tmdoit]

To get rid of additional function node for query I've created proposal to add mustache support to fixed statement editor: SQLite - Add support for mustache in fixed statement
To get rid of additional function node for result parsing and routing I propose here to add function editor - so for example I could route msg to different output based on "SELECT COUNT(*)" result (if ie. UserID not exists return 404 status code, else process further).