fix(model): throw error if calling create() with multiple docs in a transaction unless ordered: true

[vkarpov15]

Fix #15091

Summary

MongoDB does not allow multiple operations on a single transaction in parallel. Since Mongoose create() uses save() under the hood, Mongoose cannot reliably create() multiple docs in a transaction unless ordered: true is set.

Examples

[hasezoey]

Actually, tests require fixing:
Replicaset tests:

  1) transactions
       distinct (gh-8006):
     MongooseError: Cannot call `create()` with a session and multiple documents unless `ordered: true` is set
      at Function.create (lib/model.js:2623:11)
      at Context.<anonymous> (test/docs/transactions.test.js:347:21)
      at process.processTicksAndRejections (node:internal/process/task_queues:105:5)

  2) transactions
       throws error if using `create()` with multiple docs in a transaction (gh-15091):
     OverwriteModelError: Cannot overwrite `Test` model once compiled.
      at NativeConnection.model (lib/connection.js:1395:13)
      at conn.model (test/common.js:78:18)
      at Context.<anonymous> (test/docs/transactions.test.js:673:24)
      at process.processImmediate (node:internal/timers:491:21)

[vkarpov15]

Will merge this into 8.10 to be cautious