Someone cited citations I used without citing my work and effort in finding the references
No, this is not plagiarism, unless the authors specifically used the same wording as you. Citing the same sources as another paper is not plagiarism, otherwise anyone who cites an influential paper would be guilty of plagiarism unless they also cited the hundreds of other papers who also cited that influential paper.

In your specific case, you say 


  Out of the 6 examples 4 are exactly the same in my publication with 3
  of them using the same exact citations I used. Which made me believe
  with zero doubt that the one of the conference paper authors read my
  workshop paper and found those applications and citations useful and
  decided to reuse them in their publication without giving my work
  proper citation for finding those references.


This is speculation, and you can not know that this is indeed what happened. It is also quite likely that the authors did a literature review or simply knew parts of the literature, and found examples of applications that were relevant for their paper. Using the "exact same citations" is what is supposed to happen when you cite the same work.

Unless your paper is relevant and related to the work done in their paper, there is no reason for them to cite your paper, and citing work that is related to both your papers can not be considered plagiarism. At worst, you could argue that the authors should have included your paper in their related work.

Remember, people cite your papers for the work that you describe in that paper, not for the citations you give.