GONRG-1498: Move CSP dependencies to provider folder 1/2.

src/dags/providers/__init__.py

src/dags/providers/blob_storage/__init__.py

src/dags/providers/blob_storage/base_client.py

src/dags/providers/blob_storage/gcp_client.py

src/dags/providers/constants.py

src/dags/providers/credentials/__init__.py

src/dags/providers/credentials/base_credentials.py

src/dags/providers/credentials/gcp_credentials.py

src/dags/providers/exceptions.py

tests/providers-unit-tests/__init__.py

tests/providers-unit-tests/data/fake_sa_file.json

tests/providers-unit-tests/test_blob_storage_client.py

tests/providers-unit-tests/test_credentials.py

tests/providers-unit-tests/test_gcp_blob_storage_client.py

tests/providers-unit-tests/test_gcp_credentials.py

tests/unit_tests.sh