Extend UI/CGame Api with DrawStretchRaw method

[Exmirai]

Multiplayer

That feature would be useful in case if someone :) would like to throw away vanilla ui and replace it with something else. Can we implement this? I could make it myself in "ext" sections of uiImport_t/cgameImport_t

[ensiform]

Stretch raw is only used for cinematic, use a different path instead imo