Given an Inputfield name, return the child Inputfield or NULL if not found.
This traverses all children recursively to find the requested Inputfield.
This is the same as the
InputfieldWrapper::get() method except that it can
only return Inputfield or null, and has no crossover with other settings,
properties or API variables.
$inputfield = $inputfieldWrapper->getChildByName(string $name);
API reference based on ProcessWire core version 3.0.200