Add new map::has_nearby_table function

The algorithm for nearby table location is done in at least 3 places:

- src/activity_handlers.cpp:L412-419
- src/activity_item_handling.cpp:L1428-1435
- src/consumption.cpp:L845-850

Moving `has_nearby_table` as a new function it into map.cpp made it
obvious that this is where it actually belongs; there it can fit neatly
alongside its brethren like `has_nearby_fire`.

This commit only adds the new function; refactoring will come next.

src/map.cpp

@@ -2587,6 +2587,19 @@ bool map::has_nearby_fire( const tripoint &p, int radius )
     return false;
 }
 
+bool map::has_nearby_table( const tripoint &p, int radius )
+{
+    for( const tripoint &pt : points_in_radius( p, radius ) ) {
+        const optional_vpart_position vp = veh_at( p );
+        if( has_flag( "FLAT_SURF", pt ) ) {
+            return true;
+        }
+        if( vp && ( vp->vehicle().has_part( "KITCHEN" ) || vp->vehicle().has_part( "FLAT_SURF" ) ) ) {
+            return true;
+        }
+    }
+}
+
 bool map::mop_spills( const tripoint &p )
 {
     bool retval = false;

src/map.h

@@ -681,6 +681,11 @@ class map
         // "fire" item to be used for example when crafting or when
         // a iuse function needs fire.
         bool has_nearby_fire( const tripoint &p, int radius = 1 );
+        /**
+         * Check whether a table/workbench/vehicle kitchen or other flat
+         * surface is nearby that could be used for crafting or eating.
+         */
+        bool has_nearby_table( const tripoint &p, int radius = 1 );
         /**
          * Check if creature can see some items at p. Includes:
          * - check for items at this location (has_items(p))