Starting next month, passengers catching morning flights out of Boston Logan International Airport will be able to go through a Transportation Security Administration screening outpost in Framingham, Mass., rather than a terminal. Shuttle buses will then whisk them roughly 25 miles to the airport, where they will be dropped off beyond the security checkpoint, avoiding crowded parking lots, chaotic curbsides and flight check-in queues. Passengers will be able to check in and drop their bags at the remote terminal in Framingham, housed in a newly constructed temporary building.