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/phosphor-regulators/test/meson.build b/phosphor-regulators/test/meson.build
index 74695be..3373abb 100644
--- a/phosphor-regulators/test/meson.build
+++ b/phosphor-regulators/test/meson.build
@@ -24,7 +24,6 @@
     'sensor_monitoring_tests.cpp',
     'sensors_tests.cpp',
     'system_tests.cpp',
-    'temporary_file_tests.cpp',
     'write_verification_error_tests.cpp',
 
     'actions/action_environment_tests.cpp',
@@ -72,7 +71,8 @@
                 build_rpath: get_option('oe-sdk').allowed() ? rpath : '',
                 link_with: [
                     phosphor_regulators_library,
-                    libi2c_dev_mock
+                    libi2c_dev_mock,
+                    libpower
                 ],
                 implicit_include_directories: false,
                 include_directories: [