Passing context storage (#3941)

server/api.go

server/api_test.go

server/deviceflowhandlers.go

server/handlers.go

server/handlers_test.go

server/introspectionhandler.go

server/oauth2.go

server/oauth2_test.go

server/refreshhandlers.go

server/rotation.go

server/rotation_test.go

server/server.go

server/server_test.go

storage/conformance/conformance.go

storage/conformance/transactions.go

storage/ent/client/authcode.go

storage/ent/client/authrequest.go

storage/ent/client/client.go

storage/ent/client/connector.go

storage/ent/client/devicerequest.go