Akka.TestKit: configurable expect-no-message-default value #6675

[YariSPB]

A proposed solution for Akka.TestKit: configurable expect-no-message-default value #6675 task
implements 'expect-no-message-default' setting in the Akka.NET testkit for configuring ExpectNoMessage / ExpectNoMessageAsync timeouts independently from the ExpectMsg / ExpectMsgAsync.

Fixes #

• appended Reference.conf with a configuration 'expect-no-message-default' = 3s
• exposed new public property NoMessageRemainingOrDefault in TestKitBase.cs based on a new config value
• in TestKit_Expect.cs, bounded ExpectNoMsg and ExpectNoMsgAsync, which has only cancellation token as an argument, to new property.
• updated unit test

A documentation at https://getakka.net/api/Akka.TestKit.TestKitBase.html will need to be updated.

Checklist

For significant changes, please ensure that the following have been completed (delete if not relevant):

• This change follows the Akka.NET API Compatibility Guidelines.
• This change follows the Akka.NET Wire Compatibility Guidelines.
• I have reviewed my own pull request.
• Design discussion issue #
• I have added website documentation for this feature.