When a full code is passed to recoverNearest, upper case it
When a full code is passed to recoverNearest, upper case it

Implements behavior specified in https://github.com/google/open-location-code/issues/128

Reviewed https://github.com/google/open-location-code/commit/e5a9216be433b6f4464c80e126e8c1f8b0266088#diff-0a717cb928d23561819cf0be1b3f75ed, Swift implementation was already returning the full code, but now upper-cases it too.

google/open-location-code-swift,google/open-location-code-swift,google/open-location-code-swift