style: reformat C/C++ sources and headers with clang-format

Run clang-format over all project C/C++ source and header files
(.c, .cpp, .cc, .h, .hpp, .hh, .m, .mm) under app/ and tests/.
Non-source files (svg, qm, qrc, etc.) were not touched.

tests/gtest/shader_resources_test.cpp

@@ -51,8 +51,8 @@ TEST(Shaders, ResourcesAvailable)
 
 	for (const QString &path : shader_paths) {
 		QFile file(path);
-		ASSERT_TRUE(file.exists()) << "Missing shader resource: "
-								   << path.toStdString();
+		ASSERT_TRUE(file.exists())
+			<< "Missing shader resource: " << path.toStdString();
 		ASSERT_TRUE(file.open(QIODevice::ReadOnly))
 			<< "Failed to open shader resource: " << path.toStdString();
 		const QByteArray contents = file.readAll();