rm nexus sdk usage and dependency (#407)

* rm sdk usage from bluebrainexus store file

* rm sdk usage from utils

* rm sdk usage from service

* rm nexussdk from test

* lint

* fix patch

* change usage of project_fetch function for successful patching in tests

* rename module of sdk methods

* remove leftover image from store

* missing file

* restore config

* remove s from file name

* missing the file, again

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Co-authored-by: Cristina E. González-Espinoza <crisbeth46@gmail.com>

Author: ssssarah