Better display table organization on desc table via primary key list

In cqlsh, the desc table command does not make it sufficiently clear which columns are part of the row key and which are clustering keys.

A simple change to the primary key list, though, would make it easier to tell.

Consider the following table definition:

create table my_table {
  first_column text,
  second_column text,
  third_column text,
  primary key (first_column, second_column, third_column)
}

This table has a row key of first_column and clustering keys of second_column, third_column. But if the user intended for the table to have all three in the row key, the correct definition would be:

create table my_table {
  first_column text,
  second_column text,
  third_column text,
  primary key ((first_column, second_column, third_column))
}

But this is a sufficiently subtle difference that the first may be mistaken for the second or vice-versa.

My suggested solution is to always wrap the row key in parentheses. This is already supported by create table syntax, so it's just a matter of changing desc table to display the create table statement with the primary key always in parentheses, like so:

create table my_table {
  first_column text,
  second_column text,
  third_column text,
  primary key ((first_column), second_column, third_column)
}