Migrate package usages from amap_flutter_base to amap_flutter_base_clx across example and library code. Remove unused imports, tidy formatting (add trailing commas, reformat multi-line calls/constructors), and simplify several method channel invocations for readability. Add new third_party/amap_flutter_base/lib/amap_flutter_base_clx.dart with the library parts and replace the original amap_flutter_base.dart with a stub TODO. Update exports and type imports to reference the new clx variant.