f094566f54
Example CMakeLists duplicated the same dependency discovery and link setup. Move that into brpc_example_find_common_deps in BrpcExample.cmake, migrate MySQL and other examples to use it, and implement the helper as a macro so CMAKE_PREFIX_PATH, include paths, and DYNAMIC_LIB propagate to the caller scope. Example-specific deps stay local (e.g. readline/ncurses/thriftnb for MySQL, gperftools for redis/http). LINK_SO behavior is unchanged.