Contribution to SE is professional service, not research
Posting questions and answers on SE ---whilst a valuable professional service--- is not considered to be academic research. Questions and answers on SE are not peer-reviewed and do not usually involve the level of detailed study of a subject or novel contribution to a subject that would be accepted as academic research. Occasionally one will encounter answers on technical forums in SE that have some useful novel insight that might serve as the basis for an academic paper, but that would usually require much more development and a peer-review process before being counted towards research in an academic CV.
While the contribution of questions and answers on SE is not academic research, most universities will count substantial contributions on SE as professional service. Usually this would require posting high-quality answers rather than just posting questions, and a sustained contribution with relevant indicators of esteem (e.g., a high "reputation" metric, "people reached", etc.) would show that the contribution is substantial. For this reason, if you have made a substantial contribution to a relevant forum, and can show evidence of that through relevant metrics, it is acceptable to refer to such contributions on your CV or mention them in applications for admission or a funding application where relevant. This would be listed as a form of professional service rather than research. As to how this is perceived, that will differ according to who is reading your application --- some will consider this irrelevant and some will consider it something of value. As with anything you list on your CV, the main thing is to make a judgment about whether the item you are listing is of sufficient value to warrant inclusion.
For your particular case your own contribution to SE is relatively small (based on your present metrics) but you are only applying to a Masters program, so expectations for professional service would not be large. Your contribution of questions might act as an indicator of a modest amount of professional service and it could potentially illustrate your curiosity and interest in the discipline. High-quality answers are generally better than questions at illustrating existing knowledge, but high-quality questions can also be a valuable professional service. Speaking only for myself, I would not be put off by an applicant with your contribution listing this on their CV or resume, though it would be unlikely to move the needle. If you decide to list your contributions, do not list them as academic research, since that would be perceived negatively; instead list them as professional service and keep your contribution in perspective.