Don't crash on JSON load if datasets are missing

[calcmogul]

Reported by https://www.chiefdelphi.com/t/sysid-crashes-whilst-opening-previously-saved-json-data/414812/

Could be this for loop.

sysid/sysid-application/src/main/native/cpp/analysis/AnalysisManager.cpp

Lines 109 to 111 in 676478a

	for (auto&& key : AnalysisManager::kJsonDataKeys) {
	data[key] = m_json.at(key).get<std::vector<Data>>();
	}