[BUG]: Eventhub consumer group is case insensitive but storage is not

Describe the bug When using consumer groups there is a mismatch between what is accepted as name of ConsumerGroup vs Storage og state, and it can in fact be created several states per consumergroups.

To Reproduce Steps to reproduce the behavior:

1. Create a consumergroup in a eventhub called “consumer1”
2. Spin up a consumer for this eventhub
3. Send a batch of events.
4. Reconfigure this consumergroup in configuration of code (2) to be “Consumer1”
5. Entire set of events in eventhub is in fact replayed.

Given that the consumergroup is called “consumer1” then it is possible to configure and access this consumergroup with all other caseings like “Consumer1”, “COnsumer1” etc. but there will be created a new state for each version in Storage:

  ../consumer1/
  ../Consumer1/
  ../COnsumer1/

Expected behavior

If eventhub consumer groups are allowing access based upon case insensitivity, then the storage of state should also be case insensitive. In storage only one folder should exist:

  ../consumer1/

If not then changing caseing in consumergroup from the actually created consumergroup should not be allowed. Accessing consumergroup “consumer1” with configuration of consumergroup “Consumer1” should fail.

Setup (please complete the following information):

• OS: Azure, Azure Functions, but same for all users of Eventhub with this SDK
• IDE : NA
• Version of the Library used: Azure Functions 2.0, azure eventhub extensions as default.

Information Checklist Kindly make sure that you have added all the following information above and checkoff the required fields otherwise we will treat the issuer as an incomplete report

• Bug Description Added
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[jfggdl]

@helgeu, Thank you for creating this issue and linking to a previous one. Serkant is looking at the issue.

[serkantkaraca]

Doc update is tracked at https://github.com/MicrosoftDocs/azure-docs/issues/60813