Microsoft has a set of process utilities available on their website in their sysinternals section. There's one nice tool in there called pssuspend, which can stop and resume processes. Next step is merely a batch file containing the commands to pause GTA5, wait 10 seconds, then resume it.
Here's a download of it all ready to go. Just extract the two files wherever you'd like, as long as they're in the same directory. Here's a guide to bind a hotkey.
If you don't want to download random files from crazy people on the internet, you can just snag the pssuspend tool I've linked above from the official Microsoft website then make your own bat file with this inside.
That's all it is. Small microsoft program which pauses your game for 10 seconds. No modifications to anything in your game, just in case you were worried about that.pssuspend GTA5.exe
pssuspend -r GTA5.exe