Add xrpld build option and Conan package test (#5052)

* Make xrpld target optional

* Add job to test Conan recipe

* [fold] address review comments

* [fold] Enable tests in workflows

* [fold] Rename with_xrpld option

* [fold] Fix grep expression

examples/example/src/example.cpp

@@ -0,0 +1,8 @@
+#include <cstdio>
+
+#include <xrpl/protocol/BuildInfo.h>
+
+int main(int argc, char const** argv) {
+    std::printf("%s\n", ripple::BuildInfo::getVersionString().c_str());
+    return 0;
+}