[BROKEN] FieldHandlerInterface changes (task #5061)
[BROKEN] FieldHandlerInterface changes (task #5061)

FieldHandlerInterface changed as per the following:

* `__construct()` now requires a single parameter of ConfigInterface
  type.
* `setConfig()` method added for setting field handler configuration.
* `getConfig()` method added for getting field handler configuration.

QoboLtd/cakephp-csv-migrations,QoboLtd/cakephp-csv-migrations