rd53b hit generator/encoder as part of CI

rd53b generator/encoder is implemented in classes libRd53b/Rd53bEncodingTool and libRd53b/Rd53bChipMap. This generator replaces the hard-coded event sample in libRd53b/tests/test_data_processor.cpp, and for each run of the test generates a new random sample based on a seed provided by the unit test framework. The truth and encoded data can be obtained elsewhere by e. g.

#include "Rd53bEncodingTool.h"
...
std::unique_ptr<Rd53bEncodingTool> encoder(new Rd53bEncodingTool());
encoder->setSeed(0);
encoder->setEventsPerStream(16);
encoder->generate(28);
FrontEndData truthData = encoder->getTruthData();
std::vector<uint32_t> words = encoder->getWords();