Renamed the included .ain file to prevent it from overriding custom AI nodegraphs

Changes:
-Added a room under the subway station in Central Square for player moderation/other purposes
-Added sloping sidewalks in front of enterable buildings in Central District for more convenient curbside parking
-Adjusted appearance of street puddle reflections
-Fixed minor clipping issues around the map
-Fixed club spotlights not showing up properly when gmod_mcore_test is enabled
-Fixed the conveyor belt in the warehouse in Union City
-Blocked the ability to climb through the bank teller booths
-Fixed non-solid stall doors in the park's public toilets
-The electrified subway tracks near tunnel entrances/exits no longer kill you and will push you away instead

The link to a separate Navmesh addon for the map is included in the description

Initial addon creation.