code re usability is missing

[sivakumarkoduru]

https://github.com/vuefront/opencart/blob/master/catalog/model/extension/d_vuefront/address.php

https://github.com/opencart/opencart/blob/master/upload/catalog/model/account/address.php

compare above files.

We should use opencart model objects instead of that again writing same code in files.

we will miss important opencart core code changes.

for example in latest version string casting is there in sql quereis.please check above opencart model address file.

i hope you got my point.