Exposed more interfaces to builder for setting column metadata

1.Added isUnsigned, isZeroFill, isCollationWithBin and typeValues into
MySQLColumn metadata
2.Updated the logic for generating column
2.1 if columntype is not null, it means we use parsed metadata to
generate, we just use columntype.
2.2 if columntype is null, it means the metadata values are set, we
have to assemble some values into columntype.