> Does then ліки mean medicine as a science or treatment?
No, that would be медицина.
> How to say medicines/medicaments in Ukrainian?
Ліки (only plural), медикамент(и).
> According to Cambridge International Dictionary of English, it is possible to say: One of my medicines tastes of strawberries.
In this case, you have several different kinds of drugs (countable) and one of them tastes of strawberries. In Ukrainian: "Один з моїх медикаментів має присмак полуниці."