Disable case-insensitive index on _User

New Feature / Enhancement Checklist

• I am not disclosing a vulnerability.
• I am not just asking a question.
• I have searched through existing issues.

Current Limitation

Currently while Parse Server is starting up, on MongoDB, it tries to create a few indexes with case-sensitive on, on collection _User.

However not all MongoDB supports case-sensitive, for example, Azure Cosmos DB for Mongo does not support: Supported Indexes. This leads to Parse Server connecting to such database directly fails to start.

Feature / Enhancement Description

With switches of options / environment toggled on, skipping validating / creating such indexes. I see the options in PR #5634 but I don't know why that's not implemented finally.

Example Use Case

1. Add switches in options (just like PR #5634)
2. Check the switches in Controllers - DatabaseController - performInitialization method
3. Skip some calls to ensureIndex when the switches in options are turned on

Alternatives / Workarounds

No. We cannot create case-insensitive indexes on Azure Cosmos DB and we cannot disable creating such indexes in Parse. Totally not working.

3rd Party References

Not necessary.

Start by reviewing PR #5634 and the DatabaseController.performInitialization method mentioned in the issue. Trace the ensureIndex calls for the _User collection and determine which options should control them; done means Parse Server can start against MongoDB services that do not support these case-insensitive indexes while existing initialization remains unchanged.