Obstacle Type Selection Improvement

[rvhuang]

Redesign the current obstacle type selection UI. After this issue is closed, the minimum map size can be reduced.

[rvhuang]

The first draft of the new UI design is to open the obstacle selection menu by holding the left button on the map.

[rvhuang]

The design has changed to a drop-up button with a square menu.

[rvhuang]

Done!