[VOL-3860] redis client support in voltha-lib-go

redis client support has been added in this patch. There are two
types client `redis` and `redis-sentinel` to connect a redis instance.
redis-sentinel is required to be able to find the master redis
instance from a redis-sentinel process. See redis-sentinel usage
https://redis.io/topics/sentinel and
https://pkg.go.dev/github.com/go-redis/redis/v8#NewFailoverClient
for more information. If there is no need to have any failover
mechanism then the redis client type is the option to choose.

Change-Id: I997ed92115a9d565df632c6dd8184b9bab77b991
diff --git a/vendor/go.opentelemetry.io/otel/.gitmodules b/vendor/go.opentelemetry.io/otel/.gitmodules
new file mode 100644
index 0000000..38a1f56
--- /dev/null
+++ b/vendor/go.opentelemetry.io/otel/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "opentelemetry-proto"]
+	path = exporters/otlp/internal/opentelemetry-proto
+	url = https://github.com/open-telemetry/opentelemetry-proto