Added game time limit, property game_ended of overcooked_environment returns true when time limit is reached. GUI switches to game end screen when it is finished.

Resolve "Environment has internal time not datetime now"

Closes #55

See merge request scs/cocosy/overcooked-simulator!24

# Conflicts:
#	overcooked_simulator/overcooked_environment.py

Resolve "Game menus start and end"

Closes #54

See merge request scs/cocosy/overcooked-simulator!23

# Conflicts:
#	overcooked_simulator/gui_2d_vis/overcooked_gui.py

Resolve "Positions based on grid not pixels"

Closes #56

See merge request scs/cocosy/overcooked-simulator!25

fixed position of items held by the player in gui

Read grid size from viz config. Or change flag to use fixed window width, with grid size beeing rescaled

Changed world coordinate frame to unit length * number of counters in the layout. World size is determined by kitchen layout

Resolve "Mark counter to interact with"

Closes #53

See merge request scs/cocosy/overcooked-simulator!21

Changed wrong array init shape, changed wrong color usage in gui (used color names instead of rgb values)

Fixed determining closest counter and if the player can reach it. Added flags in gui to show ranges and interaction points

Resolve "Plate washing cycle"

Closes #50

See merge request scs/cocosy/overcooked-simulator!20

staticmethod