Box scopes params and methods - improved error reporting

[nimmolo]

Add useful UI error message for any missing PatternSearch params in north, south, east, west if any others are present, rather than dropping the other params silently. Also, automatically flop north and south if south > north.

Adds new tests.

[coveralls]

coverage: 93.38% (+0.003%) from 93.377%
when pulling dc84336 on nimmo-box-scopes-params-and-methods
into c1be379 on main.