Unintuitive sun specularity time of day dependence

On a similar line to #6188 (closed), specular mapped objects become completely matte at nighttime because specular component for sun is disabled at night. This also occurs during inclement weather including, ironically, rain. This was apparently done so an invisible sun wasn't throwing shimmering light on the water surface, but turning off specular altogether is overkill. Later TES games disable sun specular only for water, while all other specular-mapped objects are still able to glisten in the "moonlight".

Addendum by Capo, 29.10.23:
Due to the same mechanism, sun specularity becomes significantly weaker at dawn and dusk for both normal objects and water, which could be improved upon.