Refactoring method to get code points and code point count.

native/jni/src/suggest/core/dictionary/dictionary.cpp

...est/core/policy/dictionary_structure_with_buffer_policy.h

...ary/structure/backward/v402/ver4_patricia_trie_policy.cpp

...onary/structure/backward/v402/ver4_patricia_trie_policy.h

...tionary/structure/pt_common/dynamic_pt_reading_helper.cpp

...ictionary/structure/pt_common/dynamic_pt_reading_helper.h

...licyimpl/dictionary/structure/v2/patricia_trie_policy.cpp

...policyimpl/dictionary/structure/v2/patricia_trie_policy.h

...mpl/dictionary/structure/v4/ver4_patricia_trie_policy.cpp

...yimpl/dictionary/structure/v4/ver4_patricia_trie_policy.h