Review search module

[Peque]

• Code clean up.
  • compass_direction enum (maybe bad idea to assign values to the enum).
  • update_distances_breath: unify EAST - EAST_BIT, etc.?
  • Unify relative/absolute references? At least make the API clearer to know which one is expected/used.
  • Create dictionary-like arrays for translating sides and directions? (mmsim like)
  • #268
  • #269?
• Docstrings.