Refactoring of the information message observer test and option test

[akshita31]

1. Extracted a common getVSCodewithconfig function to be used by the tests.
2. Added the 'getVsCode` helper in the information message observer tests.
3. Added updateConfig function to be used with the fake vscode

[codecov]

Codecov Report

Merging #2277 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #2277   +/-   ##
=======================================
  Coverage   59.81%   59.81%           
=======================================
  Files          78       78           
  Lines        3773     3773           
  Branches      543      543           
=======================================
  Hits         2257     2257           
  Misses       1343     1343           
  Partials      173      173

Flag	Coverage Δ
#integration	50.86% <ø> (ø)	⬆️
#unit	83.45% <ø> (ø)	⬆️

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