Cache Images downloaded from the web

[Kulltero]

Avoids Re-downloading the same image for following instances of the same image, re-using the texture instead, doesnt persist through restarts

(Also Removing a now-useless if check, since it shouldnt happen and would only confuse anyone if it did, this was left from my change to prevent mipmap issues)

i chose not to use the CachedTexture system added in a recent commit, because sprites cant currently be loaded from the web & there didnt seem to be a trivial way to get the CRC just from the url, feel free to change it over if desired 👍