Reduce CPU cycles spent on setting tracing tags

[RohanNagar]

Make sure that:

• You have read the contribution guidelines.
• You have created a feature request first to discuss your contribution intent. Please reference the feature request ticket number in the pull request.
• You applied code formatting rules using the mvn formatter:format target. Don’t submit any formatting related changes.
• You submit test cases (unit or integration tests) that back your changes.

Addresses #3308 to avoid creating a RedisURI object when setting tracing tags. As explained in the issue, the current behavior results in unnecessary CPU usage.

This change caches the necessary information that is added to span tags each time the channel is registered.

This should work as long as the RedisUri attribute attached to the channel doesn't change (is that a correct assumption?).

The alternative is to just extract the information each time from channel.attr(ConnectionBuilder.REDIS_URI).get(). Something like:

        if (channel.hasAttr(ConnectionBuilder.REDIS_URI)) {
            String redisUriStr = channel.attr(ConnectionBuilder.REDIS_URI).get();
            span.tag("server.address", redisUriStr);
            span.tag("db.namespace", extractedDbValueFromRedisUriStr);
            span.tag("user.name", extractedUsernameValueFromRedisUriStr);
        }