unittests for TC and CCSDS distributor

unittests/mocks/CcsdsCheckerMock.cpp

@@ -0,0 +1,10 @@
+#include "CcsdsCheckerMock.h"
+
+CcsdsCheckerMock::CcsdsCheckerMock() = default;
+
+ReturnValue_t CcsdsCheckerMock::checkPacket(const SpacePacketReader& currentPacket,
+                                            size_t packetLen) {
+  checkCallCount++;
+  checkedPacketLen = packetLen;
+  return nextResult;
+}