This dirty soda/energy drink mash-up is now taking over TikTok.Credit: Candra Syahroni / Getty ImagesThe Pacific Northwest is arguably one of the country’s most caffeinated regions. On a recent road trip across Snohomish County, I found that the area may be getting a caffeine boost from an unlikely source. Instead of traditional coffee shops, drive-thru coffee stands seem to be everywhere. And instead of traditional coffee orders, many customers…