Add unit tests for digger passage and room functions.
Add unit tests for digger passage and room functions.

New tests for `digger_dig_passage()` and `digger_dig_room()`.

Added new checks to some tests to verify the ending position of the
digger after a digger function is called.

Consolidated redundant tests
`digger_dig_chamber_test_for_adjacent_areas_with_padding_zero()` and
`digger_dig_chamber_test_for_adjacent_areas_with_padding_one()` into
`digger_dig_chamber_test_for_overlapping_areas()`.

donmccaughey/FiendsAndFortune,donmccaughey/FiendsAndFortune,donmccaughey/FiendsAndFortune