Add `client_options` to constructors for manual clients.

[busunkim96]

List of clients is copied from the issue for client_info. See #7825.

The client_options constructor argument provides a consistent way for options to be set on clients. Currently only API Endpoint can be set with client_options.

GAPIC clients will gets this change via the generator, but the clients below need to be updated manually.

Clients that need client_options:

• BigQuery BigQuery: Add client_options to constructors for manual clients. #8999
• Bigtable feat(bigtable): add 'client_options' / 'admin_client_options' to Client #9517
  • data endpoint
  • admin endpoint
• Datastore Datastore: Add client_options to constructors for manual clients. #9055
• DNS feat(dns): add 'client_options' argument to client ctor #9516
• Error Reporting Error Reporting: Add client_options to constructor. #9152
• Firestore (and Firestore Beta) Firestore: Add client_options to v1. #9048
• Logging Logging: Add client_options to v1 #9046
• Pub/Sub (Publisher, Subscriber) (done via **kwargs)
• Resource Manager Resource Manager: Add client_options. #9043
• Runtime Config Runtime Config: Add client_options #9045
• Spanner feat(spanner): add client_options to constructor #9151
  • Client.instance_admin_api
  • Client.database_admin_api
  • Database.spanner_api
• Storage Storage: Add client_options to constructors for manual clients. #9054
• Trace and Trace V1 feat(trace): add client_options to constructor #9154
• Translate (no GRPC version needed, because v3beta1 is pure-autogen) Translate: Add client options to translate_v2. #8737