Feature request: getConnection timeout

[CarlOlson]

I ran into a problem where a service caused a deadlock by waiting on getConnection. Here is a rough example of the code:

await pool.withTransaction(async tx => {
  await service.prepare()
  await doSomething(tx)
})

Many long-running requests caused the pool to saturate, then the service caused a deadlock and kept the transaction open. This is easily fixed by not giving service the pool, or by checking that we aren't already in a transaction.

However, a timeout could be useful to avoid these unexpected situations:

// 5s timeout on getConnection
const pool = createPool({ acquireTimeout: 5_000 });

// and/or
await pool.getConnection({ timeout: 1_000 })

// or with signals
await pool.getConnection({ signal: AbortSignal.timeout(1_000) })

A timeout can be implemented by users, but they can't remove the request from the queue on timeout. There is also a gotcha that leaks connections if not implemented correctly. So, I think this should be a library feature.