Expose network timeout consumer configs via client profile
Expose network timeout consumer configs via client profile

This change allows users to set initial connection & RPC response read timeouts
for kafka client. The underlying sarama lib has these two documented as,

```
DialTimeout  time.Duration // How long to wait for the initial connection.
ReadTimeout  time.Duration // How long to wait for a response.
```

Through these configs, one could deal with slow responding brokers and avoid
i/o timeouts.

The change also includes minor refactoring to keep the linter happy,
s/time/timestamp to avoid overshadowing from the new 'time' import

linkedin/Burrow