Enable Selective Service Imports

If users experience slowdowns in their applications/scripts while importing the oci module for python SDK, then, they can disable importing all the services (enabled by default) by setting the following environment variable:-

export OCI_PYTHON_SDK_NO_SERVICE_IMPORTS=True

After enabling this, users will have to import individual services and modules that are needed in place of the import oci line. For example, the script here can be modified to:-

from oci import identity
from oci import config

config = config.from_file()

identity_client = identity.IdentityClient(config)

user = identity_client.get_user(config["user"]).data

print(user)