php bin/rector process

A couple of rectors have been disabled due to different reasons:

- Rector\Php71\Rector\FuncCall\CountOnNullRector
  This rector has been disabled as it creates rather long and
  complex structures to avoid calling count on null.

  This rector will be enabled as soon as TYPO3 uses at least
  PHP 7.3 which introduces a "is_countable" method.

- Rector\Php71\Rector\Assign\AssignArrayToStringRector
  This rector has been disabled as it does not work properly.
  The default types of parameters have been changed although
  their types could properly be inferred by a doc block or
  by value assignments.

- Rector\Php71\Rector\BinaryOp\BinaryOpBetweenNumberAndStringRector
  This rector has been disabled as it does not work properly.
  A bug report is filed and to be found here:
  https://github.com/rectorphp/rector/issues/2454

- Rector\Php71\Rector\FuncCall\RemoveExtraParametersRector
  This rector has been disabled as it does not work properly.
  It re...