[#14][Code] move pollEvents to Core.beginFrame()

hides poll events from User, so i can't be forgotten

projects/first_triangle/src/main.cpp

@@ -102,8 +102,6 @@ int main(int argc, const char** argv) {
 		core.beginFrame();
 	    core.renderTriangle(trianglePass, trianglePipeline, windowWidth, windowHeight);
 	    core.endFrame();
-
-		window.pollEvents();
 	}
 	return 0;
 }

src/vkcv/Core.cpp

@@ -154,7 +154,7 @@ namespace vkcv
     	if (acquireSwapchainImage() != Result::SUCCESS) {
     		return;
     	}
-		
+		m_window.pollEvents();
 		m_Context.getDevice().waitIdle();	// FIMXE: this is a sin against graphics programming, but its getting late - Alex
 		destroyTemporaryFramebuffers();
 		const vk::CommandBufferUsageFlags beginFlags = vk::CommandBufferUsageFlagBits::eOneTimeSubmit;