Add support for loading relational data, object brick and field collection

[prunepal333]

Add support for loading relational data, object brick and field without preloading/creating the data in mapper
For an instance, an object is having attributes (manyToOneRelation, manyToManyRelation, objectBrick, fieldCollection etc.)

My idea would be to follow a convention over configuration for each type similar to LocalisedField (Line 90 in BaseImporter.php)
Sample code:
BaseImporter.php

        foreach ($data['attributes'] as $attribute => $value) {
            if ($attribute == 'localisedField' && is_array($value)) {
                $dataObject = $this->attachLocalisedField($value, $dataObject);
            } else if ($attribute == 'relationField') {
                //$value is scalar, it is manyToOneRelation
                //$value is array, it is manyToManyRelation
               //metadata can be passed as key-value pair for advanced relations as optional data params
                 $dataObject = $this->attachRelationField($value, $dataObject );
            } 
           else if (condition) { // array with string indexing is assumed to be object brick by default
           }
          else if (condition) { //array with numeric indexing is assumed to be fieldcollection by default
          }else {
                $setterMethod = 'set' . ucfirst($attribute);
                if (method_exists($dataObject, $setterMethod)) {
                    match ($setterMethod) {
                        'setKey' => $dataObject->$setterMethod($this->slugify->slugify($value)),
                        default => $dataObject->$setterMethod($value)
                    };
                }
            }
        }

BaseImporter can be added with procedures/functions for attaching structured data types (like LocalisedField) or subclasses or BaseImporter be created to solve this issue.

[ravisharmaa]

@prunepal333 You could use better formatting to help understand your idea :)

some php code