ci: add script to check section references

tools/test_apps/system/bootloader_sections/main/CMakeLists.txt

@@ -0,0 +1,4 @@
+idf_component_register(SRCS "test_main.c"
+                       INCLUDE_DIRS ".")
+
+

tools/test_apps/system/bootloader_sections/main/test_main.c

@@ -0,0 +1,3 @@
+void app_main(void)
+{
+}