Update RabbitMQ client version to 6.2.2

[JatinSanghvi]

• Updated RabbitMQ client version from 5.1.2 to 6.2.2.
• Updated the target framework for sample and test projects. '.NET Core 2.2' is out of support since 2019.
• Updated the code to work with a breaking change introduced in 6.2.2 client.
• Fixed unit test to work with new client version.
• Verified all sample functions work as expected with the changes.

Fixes #173, #92

[kshyju]

This interface is public. So, changing the method signature will be a breaking change for anyone using this API. Do you know who uses this?

Do we need this change? If so, should we do it in a backward compatible way? (Introduce a new overload and mark the old one as obsolete).

[JatinSanghvi]

There's no public class that accepts IRabbitMQModel as its method argument or has IRabbitMQModel as return type. The only path where I could find the model definition leaking was via IRabbitMQModel <- IRabbitMQService <-IRabbitMQServiceFactory but it stops at that point. There are no public classes taking or returning either IRabbitMQService or IRabbitMQServiceFactory or any of their implementation classes. I guess customer would not be impacted if they cannot work with IRabbitMQModel in connection with any other classes in RabbitMQ extension. I will fix the visibility of the classes and interfaces in a future PR.

[kshyju]

One question about the public API surface.

[yojagad]

The general guidance is to introduce newer rabbitmq client version updates (major version updates) through a new major version of the extension.

[JatinSanghvi]

The general guidance is to introduce newer rabbitmq client version updates (major version updates) through a new major version of the extension.

Following the same tradition as of other Azure Functions repo, I will fork out v1.x branch but dev branch will continue to be the one for next minor/major release which will be 2.0.0. So the PR has correct branch set as the target.

A manual version bump is not required with new build and release pipeline.