Removed 8 unnecessary stubbings in CommunicationtTestMocker

[ARUS2023]

In our analysis of the project, we observed that the

1. CommunicationtTestMocker.mockTopology contains 1 stubbing which is created but never executed.
2. CommunicationtTestMocker.mockConfiguration contains 6 stubbings which are created but never executed.
3. CommunicationtTestMocker.mockTopologyWithTCP contains 1 stubbing (stubbed CurrentViewMembermethod) which is created but never executed in 2 tests: ServerCommunicationLayerTest.testDoubleNettyNodes and ServerCommunicationLayerTest.testNettyNodesNetwork

Unnecessary stubbings are stubbed method calls that were never realized during test execution. Mockito recommends to remove unnecessary stubbings (https://www.javadoc.io/doc/org.mockito/mockito-core/latest/org/mockito/exceptions/misusing/UnnecessaryStubbingException.html).

We propose below a solution to remove the unnecessary stubbing.