Infrared ellipsometry study of photogenerated charge carriers at the (001) and (110) surfaces of $\mathrm{SrTi}{\mathrm{O}}_{3}$ crystals and at the interface of the corresponding $\mathrm{LaAl}{\mathrm{O}}_{3}/\mathrm{SrTi}{\mathrm{O}}_{3}$ heterostructures