feat(contrib):add etcd watcher withKeysOnly option

[upuplouis]

Description (what this PR does / why we need it):

read value from etcd twice if no such opOption

Which issue(s) this PR fixes (resolves / be part of):

Other special notes for the reviewers:

[codecov-commenter]

Codecov Report

Merging #2146 (91d053d) into main (4ca25e4) will not change coverage.
The diff coverage is n/a.

❗ Current head 91d053d differs from pull request most recent head e60ed87. Consider uploading reports for the commit e60ed87 to get more accurate results

@@           Coverage Diff           @@
##             main    #2146   +/-   ##
=======================================
  Coverage   79.08%   79.08%           
=======================================
  Files          84       84           
  Lines        3696     3696           
=======================================
  Hits         2923     2923           
  Misses        560      560           
  Partials      213      213           

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[daemon365]

LGTM