Review form Yura (part 2)

* Reordered include headers (system first, then boost, then standard mysql, then udf framework)
* No c-style (.h) headers from standard library
* Introduced new "binary_charset" conatant used as a character set for functions working with binary arguments / return values.
* earlier return (exception throwing) in case of errors
* 'get_arg<STRING_RESULT>()' returns std::string_view, which is not guaranteed to be null-terminated - so, we shopuld always use the pair of iterators (std::begin(uxs), std::end(uxs)) instead of usx.data().
* introduced 'hash_uuid_namespace_type' enum (instead of 1,2,3,4)
* 'boost::uuids::random_generator' in 'uuid_v4_impl' made 'static thread_local' as it initialized with std::random_device that can be expensive.
* we now explicitly set character set for the argument (ansi) and return value(binary) in 'uuid_vx_to_bin_impl'.
* we now explicitly set character set for the argument (binary) and return value(ansi) in 'bin_to_uuid_vx_impl'.