Create regulators action_utils namespace

Create the action_utils namespace for utility functions related to the
regulators action framework.

Create a function in that namespace that executes a vector of actions.

Signed-off-by: Shawn McCarney <shawnmm@us.ibm.com>
Change-Id: I22297435daad0d5f6ad61157c094938f0488f076
diff --git a/phosphor-regulators/test/meson.build b/phosphor-regulators/test/meson.build
index 6d6df82..a60249f 100644
--- a/phosphor-regulators/test/meson.build
+++ b/phosphor-regulators/test/meson.build
@@ -10,6 +10,7 @@
     'rule_tests.cpp',
 
     'actions/action_environment_tests.cpp',
+    'actions/action_utils_tests.cpp',
     'actions/set_device_action_tests.cpp'
 ]