Default m3msg write timeouts to 5 seconds

[ryanhall07]

What this PR does / why we need it:
This changes both the Producer sending new messages and the Consumer
sending ack messages.

5s is a safer default to prevent infinite blocking if the TCP connection
is not currently available for writing (i.e the buffer is full).

Special notes for your reviewer:

Does this PR introduce a user-facing and/or backwards incompatible change?:
Yes. The default write timeouts change from unbounded to 5s.

Does this PR require updating code package or user-facing documentation?:
No

[robskillington]

Should we update the consumerWriterTimeout default to also be 5s?

[robskillington]

LGTM

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (master@47c219a). Click here to learn what that means.
The diff coverage is n/a.

@@           Coverage Diff            @@
##             master   #2698   +/-   ##
========================================
  Coverage          ?   70.0%           
========================================
  Files             ?    1091           
  Lines             ?   98151           
  Branches          ?       0           
========================================
  Hits              ?   68797           
  Misses            ?   24605           
  Partials          ?    4749           

Flag	Coverage Δ
#aggregator	75.9% <ø> (?)
#cluster	85.0% <ø> (?)
#collector	62.3% <ø> (?)
#dbnode	79.4% <ø> (?)
#m3em	68.6% <ø> (?)
#m3ninx	60.9% <ø> (?)
#m3nsch	78.0% <ø> (?)
#metrics	17.2% <ø> (?)
#msg	74.2% <ø> (?)
#query	68.9% <ø> (?)
#x	55.9% <ø> (?)

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