Error when computed_field module fields are present

Whether other modules providing fields should always implement getThurdPartySetting or not, from Field Encrypt's point of view if that is not there the field cannot be encrypted, so we can do this check and move on. That is, this protects people using Filed Encrypt from more than only Computed Field in its current state.

What does this module do for base fields, which don't support third party settings either?

This is an incorrect assumption:

      $is_base_field = $storage->isBaseField();
      // Check if the field is encrypted.
      if (
        ($is_base_field && $storage->getSetting('field_encrypt.encrypt')) ||
        (!$is_base_field && $storage->getThirdPartySetting('field_encrypt', 'encrypt', FALSE))

A field that is not a base field is not necessarily a config field. Bundle fields can be defined in code too.

Rather than doing

> method_exists($storage, 'getThirdPartySetting

in the MR, check for whether the field is a ConfigEntityInterface.