KIP 848: Extend DescribeConfigs and IncrementalAlterConfigs to support GROUP Config

[PratRanj07]

This PR intends to add support for Group Resource type for IncrementalAlterConfigs API as specified in KIP 848 and extended the DescribeConfigs support till API version 3.
Additional changed the integration test to check for Group Resource Type.
Librdkafka PR: confluentinc/librdkafka#4939

I have tested it locally and it is working fine
dotnet test --filter "FullyQualifiedName=Confluent.Kafka.IntegrationTests.Tests.AdminClient_IncrementalAlterConfigs"

Passed! - Failed: 0, Passed: 1, Skipped: 0, Total: 1, Duration: < 1 ms - Confluent.Kafka.IntegrationTests.dll (net6.0)

Passed! - Failed: 0, Passed: 1, Skipped: 0, Total: 1, Duration: < 1 ms - Confluent.Kafka.IntegrationTests.dll (net8.0)

[confluent-cla-assistant]

🎉 All Contributor License Agreements have been signed. Ready to merge.
_{Please push an empty commit if you would like to re-run the checks to verify CLA status for all contributors.}