Update example package for indirect module use

Update hello_complex_2 example package to add a non-library module that is indirectly used by an app in the same directory.

Author: LKedward

example_packages/hello_complex_2/app/say_hello/app_extra_mod.f90

@@ -0,0 +1,6 @@
+module app_extra_mod
+implicit none
+
+character(len=5) :: greet_object = "World"
+
+end module app_extra_mod

example_packages/hello_complex_2/app/say_hello/app_hello_mod.f90

@@ -1,4 +1,5 @@
 module app_hello_mod
+use app_extra_mod, only: greet_object
 implicit none
 
 integer :: hello_int = 42

example_packages/hello_complex_2/app/say_hello/say_Hello.f90

@@ -1,8 +1,8 @@
 program say_Hello
     use greet_m, only: make_greeting
-    use app_hello_mod
+    use app_hello_mod, only: greet_object
 
     implicit none
 
-    print *, make_greeting("World")
+    print *, make_greeting(greet_object)
 end program say_Hello