citra-qt: update the separate window titles to use full_name and show Primary/Secondary identifier (#6712)

* citra-qt: update the separate window titles to use full_name and Primary/Secondary window identifier

* build_fullname: remove trailing space

CMakeModules/GenerateBuildInfo.cmake

@@ -57,9 +57,7 @@ if (DEFINED ENV{CI})
             set(BUILD_VERSION ${CMAKE_MATCH_1})
         endif()
         if (BUILD_VERSION)
-            # This leaves a trailing space on the last word, but we actually want that
-            # because of how it's styled in the title bar.
-            set(BUILD_FULLNAME "${REPO_NAME} ${BUILD_VERSION} ")
+            set(BUILD_FULLNAME "${REPO_NAME} ${BUILD_VERSION}")
         else()
             set(BUILD_FULLNAME "")
         endif()