Fix all tests to work with embedded data, no CCD, part 4

src/CifUtils.cpp

@@ -1243,6 +1243,9 @@ void addDataDirectory(std::filesystem::path dataDir)
 
 void addFileResource(const std::string &name, std::filesystem::path dataFile)
 {
+	if (not fs::exists(dataFile))
+		throw std::runtime_error("Attempt to add a file resource for " + name + " that does not exist: " + dataFile.string());
+
 	gLocalResources[name] = dataFile;
 }
 

test/unit-test.cpp

@@ -1532,8 +1532,6 @@ BOOST_AUTO_TEST_CASE(bondmap_1)
 {
     cif::VERBOSE = 2;
 
-	cif::addFileResource("components.cif", gTestDir / ".." / "data" / "components.cif");
-
 	// sections taken from CCD compounds.cif
 	auto components = R"(
 data_ASN