New Rule: ban-uncommitted-transaction

Added

• linter: new rule ban-uncommitted-transaction

  Squawk now warns about missing commit statements like:

  begin;
  create table t(id bigint);

  warning[ban-uncommitted-transaction]: Transaction never committed or rolled back.
    ╭▸ stdin:1:1
    │
  1 │ begin;
    │ ━━━━━
    │
    ├ help: Add a `COMMIT` or `ROLLBACK` statement to complete the transaction.
    ╭╴
  2 ±
  3 + COMMIT;
    ╰╴