This will find all data generators that can be used in behat via the
'the following "something" exist:' step, and display them in a select
list on the step definitions page.
When a generator is selected, it will fetch the required fields for that
generator and display them on the page.
Because of the too strict input param type, the form did not allow to
search for Behat steps containing the given phrase. The patch sets the
param type to match the one in the form definition, and makes sure that
the submitted value can be safely used as a CLI script argument.
Mark Johnson