FEATURE: Better stack tracing

[dmerkushov]

Problem solved by the feature

The current stack trace in exceptions is not as clear as it can be

Description of the proposed solution

https://github.com/bombela/backward-cpp

Impact on nanoservice development

Better stack traces will enhance developer experience

Feature optionality

This is a mandatory feature

[dmerkushov]

By now, stacktraces are filled up in NsException::init():

nanoservices/ns-skeleton/src/NsException.cpp

Lines 120 to 157 in 056446f

	void NsException::init(const string &rootExStack, const string &rootExShort, const string &rootExFull) {
	void **addressArr = new void *[NSE_STACKTRACE_SIZE_MAX];
	size_t stacktraceSize = backtrace(addressArr, NSE_STACKTRACE_SIZE_MAX);
	char **stacktraceArr = backtrace_symbols(addressArr, stacktraceSize);
	std::stringstream ss;
	ss << _stacktrace << " - ";
	if (stacktraceSize >= 3) {
	for (unsigned int i = 2; i < stacktraceSize; i++) {
	ss << stacktraceArr[i] << endl;
	}
	}
	_stacktrace = ss.str();
	free(stacktraceArr);
	delete[] addressArr;
	stringstream wss;
	try {
	wss << typeid(*this).name();
	} catch (std::bad_typeid &bti) {
	wss << "(Unknown exception class)";
	}
	wss << " : " << _shortDescription << endl;
	wss << _stacktrace;
	if (rootExFull != "") {
	wss << endl << endl;
	wss << "\tCaused by:" << endl;
	wss << rootExFull;
	}
	_fullDescription = wss.str();
	_rootExceptionFullDescription = rootExFull;
	}