Initial Dijkstra algorithm for the map, but doesn't quite work right. The walls in the wall_map are not accounted for in the algorithm.

meson.build

@@ -14,14 +14,17 @@ dependencies = [catch2, fmt,
 
 runtests = executable('runtests', [
   'dbc.cpp',
+  'map.cpp',
   'tests/fsm.cpp',
   'tests/dbc.cpp',
+  'tests/map.cpp',
   ],
   dependencies: dependencies)
 
 roguish = executable('roguish', [
   'dbc.cpp',
-  'main.cpp'
+  'main.cpp',
+  'map.cpp',
   ],
   dependencies: dependencies)