Grouping statement enum by macro-categories

At this time, the statements enum is massive and includes all SQL statements. What if we were to create sub-enum categories, such as DML, DDL DQL, DCL, TCL, SCL, PSM and so on?

This would clearly break APIs, but it would make much more manageable to work with statements, expecially in the cases where only a subset of the statements are desidered.

Luca

Comece localizando o statements enum e revisando sua API pública e seus usos. Defina as macrocategorias SQL propostas e avalie as implicações de quebra da API e de compatibilidade; o trabalho estará concluído quando a estrutura de categorias e as interfaces afetadas forem acordadas e cobertas pelos testes relevantes do parser.

Escrita pelo modelo de indexação a partir do texto da issue.