when using Mongodb with mikroorm it does not recreate indexes and there seems to be no other way to drop indexes

[Loki-Afro]

Describe the bug
when using Mongodb with mikroorm it does not recreate indexes and there seems to be no other way to drop indexes.
We are using this.orm.getSchemaGenerator().ensureIndexes(); this only complaints about index definition mismatches, there is no way to simply drop indexes and recreate them in such cases.
If an orm can create indexes it should also care about their upgrade path
There is also no way to gather information from the resulting error since it basically pushed the mongodb error to the user without treating it accordingly (api leakage)

Stack trace

MongoServerError: Index with name: ldapDn_1 already exists with different options
    at MessageStream.messageHandler (/home/zarathustra/code/schulcloud-server/node_modules/mongodb/src/cmap/connection.ts:753:20)
    at MessageStream.emit (node:events:390:28)
    at processIncomingData (/home/zarathustra/code/schulcloud-server/node_modules/mongodb/src/cmap/message_stream.ts:168:12)
    at MessageStream._write (/home/zarathustra/code/schulcloud-server/node_modules/mongodb/src/cmap/message_stream.ts:65:5)
    at writeOrBuffer (node:internal/streams/writable:389:12)
    at _write (node:internal/streams/writable:330:10)
    at MessageStream.Writable.write (node:internal/streams/writable:334:10)
    at Socket.ondata (node:internal/streams/readable:754:22)
    at Socket.emit (node:events:390:28)
    at addChunk (node:internal/streams/readable:315:12) {
  ok: 0,
  code: 85,
  codeName: 'IndexOptionsConflict'
}

To Reproduce
Steps to reproduce the behavior:

1. define an entity with any kind of index
2. let mikroorm create indexes
3. change an existing index definition in an entity (nullable false -> nullable true for example)
4. rerun {{ensureIndexes}} - exception occurs

Expected behavior
Indexes get recreated with an warning, most probably with another option to enable this feature

Versions

| Dependency | Version |
| node | v16.13.1 |
| typescript | 4.2.4 |
| mikro-orm | 5.0.5 |
| your-driver | mongodb |

[Loki-Afro]

Mongoose does this as well https://github.com/Automattic/mongoose/blob/e95518b2cd871ff54cc9dcb5b1c9b40ca7dc6e04/lib/model.js#L1472

[totalard]

just put ensureindex: true in config

[B4nan]

@totalard the problem is not with ensuring indexes, but that we only care about creating new indexes, not removing old indexes nor changing redefined ones.