Add json log encoder

[clamoriniere]

What does this PR do?

Add the possibility to configure the logger with the json log encoder.

• new process arg: -logEncoder with two possible value: json and console. json is the default value.

Motivation

json log format was possible with previous version.

Additional Notes

N/A

Describe your test plan

• run the extendeddaemonset controller process with args -help to check the new arg.
• execute the extendeddaemonset controller and check that default logs are in json.
• redeploy the extendeddaemonset with -logEncoder=console to check that the format change.

[codecov-commenter]

Codecov Report

Merging #48 into v0.3 will not change coverage. The diff coverage is n/a.

@@           Coverage Diff           @@
##             v0.3      #48   +/-   ##
=======================================
  Coverage   37.46%   37.46%           
=======================================
  Files          29       29           
  Lines        1500     1500           
=======================================
  Hits          562      562           
  Misses        865      865           
  Partials       73       73           

Flag	Coverage Δ
#unittests	37.46% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update 783987c...949dd7c. Read the comment docs.