chore: import upstream snapshot with attribution

modules/highgui/cmake/detect_framebuffer.cmake

@@ -0,0 +1,14 @@
+# --- FB ---
+set(HAVE_FRAMEBUFFER ON)
+if(WITH_FRAMEBUFFER_XVFB)
+  try_compile(HAVE_FRAMEBUFFER_XVFB
+    "${CMAKE_CURRENT_BINARY_DIR}"
+    "${OpenCV_SOURCE_DIR}/cmake/checks/framebuffer.cpp")
+  if(HAVE_FRAMEBUFFER_XVFB)
+    message(STATUS "Check virtual framebuffer - done")
+  else()
+    message(STATUS
+      "Check virtual framebuffer - failed\n"
+      "Please install the xorg-x11-proto-devel or x11proto-dev package\n")
+  endif()
+endif()