This switches the input parameters for API calls to a generic
keyword argument catch-all which is then loaded into a dataclass
where the parameters are checked and forwarded to internal
function.
The dataclass gives more flexibility with the parameters and makes
it easier to reuse common parameters for the different API calls.
The initial plan to serve /details and /lookup endpoints from
the same API call turned out to be impractical, so the API now
also has deparate functions for both.
The only allowable difference is precision of coordinates. Python uses
a precision of 7 digits where possible, which corresponds to the
precision of OSM data.
Also fixes some smaller bugs found by the BDD tests.
