Move TemporaryFile class to root directory

Source code that is shared across applications is located in the root
directory of the phosphor-power repository.

The TemporaryFile class was originally created for the
phosphor-regulators application.  However it is general purpose and is
now needed by the phosphor-power-sequencer application.

Move the TemporaryFile class to the root directory.  Update C++ files
that use the TemporaryFile class since it is now in a different
namespace.  Update affected meson.build files.

Change-Id: I6d18080d2436a5da87b7ab51ac003c503caa36a3
Signed-off-by: Shawn McCarney <shawnmm@us.ibm.com>
diff --git a/test/meson.build b/test/meson.build
index 92225b4..0b4fd20 100644
--- a/test/meson.build
+++ b/test/meson.build
@@ -1,27 +1,19 @@
 test(
-    'nvtest',
+    'common-code-tests',
     executable(
-        'nvtest', 'nvtest.cpp',
+        'common-code-tests',
+        'file_descriptor_tests.cpp',
+        'nvtest.cpp',
+        'temporary_file_tests.cpp',
         dependencies: [
             gmock,
             gtest,
         ],
         link_args: dynamic_linker,
         build_rpath: get_option('oe-sdk').allowed() ? rpath : '',
-        implicit_include_directories: false,
-        include_directories: '..',
-    )
-)
-
-test(
-    'file_descriptor_tests',
-    executable(
-        'file_descriptor_tests', 'file_descriptor_tests.cpp',
-        dependencies: [
-            gtest,
+        link_with: [
+            libpower
         ],
-        link_args: dynamic_linker,
-        build_rpath: get_option('oe-sdk').allowed() ? rpath : '',
         implicit_include_directories: false,
         include_directories: '..',
     )