sdbus++: common: move PropertiesVariant from server

PropertiesVariant is currently useful outside of the server constructor,
such as cases where someone wants to create a signal match against
the PropertiesChanged signal.  Move it to common since we don't have a
better solution for signals presently.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I7ce53a8c796fac0713ac42fe29e364bf9b2e745c
diff --git a/tools/sdbusplus/templates/interface.common.hpp.mako b/tools/sdbusplus/templates/interface.common.hpp.mako
index d64090d..50893ca 100644
--- a/tools/sdbusplus/templates/interface.common.hpp.mako
+++ b/tools/sdbusplus/templates/interface.common.hpp.mako
@@ -8,6 +8,12 @@
 
 #include <sdbusplus/exception.hpp>
 #include <sdbusplus/message.hpp>
+#include <sdbusplus/utility/dedup_variant.hpp>
+<%
+    def setOfPropertyTypes():
+        return set(p.cppTypeParam(interface.name) for p in
+                   interface.properties);
+%>\
 
 namespace sdbusplus::common::${interface.cppNamespace()}
 {
@@ -25,6 +31,11 @@
     };
     % endfor
 
+    % if interface.properties:
+    using PropertiesVariant = sdbusplus::utility::dedup_variant_t<
+        ${",\n        ".join(sorted(setOfPropertyTypes()))}>;
+    % endif \
+
     % for p in interface.paths:
         % if p.description:
     /** ${p.description.strip()} */
diff --git a/tools/sdbusplus/templates/interface.server.hpp.mako b/tools/sdbusplus/templates/interface.server.hpp.mako
index 2d807fb..5d203c5 100644
--- a/tools/sdbusplus/templates/interface.server.hpp.mako
+++ b/tools/sdbusplus/templates/interface.server.hpp.mako
@@ -3,19 +3,13 @@
 #include <map>
 #include <sdbusplus/sdbus.hpp>
 #include <sdbusplus/server.hpp>
-#include <sdbusplus/utility/dedup_variant.hpp>
 #include <string>
 #include <systemd/sd-bus.h>
 
 % for h in interface.cpp_includes():
 #include <${h}>
 % endfor
-#include <${interface.headerFile()}> \
-<%
-    def setOfPropertyTypes():
-        return set(p.cppTypeParam(interface.name) for p in
-                   interface.properties);
-%>
+#include <${interface.headerFile()}>
 
 namespace sdbusplus::server::${interface.cppNamespace()}
 {
@@ -50,8 +44,6 @@
             _sdbusplus_bus(bus) {}
 
     % if interface.properties:
-        using PropertiesVariant = sdbusplus::utility::dedup_variant_t<
-                ${",\n                ".join(sorted(setOfPropertyTypes()))}>;
         /** @brief Constructor to initialize the object from a map of
          *         properties.
          *