fixed interfaces and tests, improved code in prune

channels/joinedChannel_test.go

channels/manager.go

channels/sendTracker_test.go

cmix/identity/receptionID/store.go

connect/utils_test.go

dummy/mockCmix_test.go

e2e/fpGenerator_test.go

e2e/rekey/utils_test.go

e2e/utils_test.go

fileTransfer/connect/utils_test.go

fileTransfer/e2e/utils_test.go

fileTransfer/groupChat/utils_test.go

fileTransfer/utils_test.go

groupChat/networkManager_test.go

ud/networkManager_test.go

xxdk/utilsInterfaces_test.go