[SECENG-676] added 'status' filter to decision logs fetch command

[sagar-connect]

Checklist

=========

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have checked for similar issues and haven't found anything relevant.
• This is not a security issue (which should be reported here: https://circleci.com/security/)
• I have read Contribution Guidelines.

Changes

=======

• added 'status' filter to decision logs fetch command
• updated unit-tests
• updated usage tests golden data

Rationale

=========

This is in continuation to: https://github.com/circleci/policy-service/pull/147

[codecov]

Codecov Report

Merging #753 (ff3858a) into master (f848adb) will increase coverage by 0.03%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #753      +/-   ##
==========================================
+ Coverage   31.88%   31.91%   +0.03%     
==========================================
  Files          44       44              
  Lines        5323     5326       +3     
==========================================
+ Hits         1697     1700       +3     
  Misses       3382     3382              
  Partials      244      244              

Impacted Files	Coverage Δ
api/policy/policy.go	65.86% <100.00%> (+0.41%)	⬆️
cmd/policy/policy.go	82.02% <100.00%> (+0.08%)	⬆️

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