[DREAM-802] Show blankslate on empty filter

Filtering the phase definitions to no matches left a bare header box
with a detached plain-text notice below it. The list's own empty state
now appears inside the box through the dynamic lifecycle.

https://community.openproject.org/wp/DREAM-802

Author: myabc

app/components/settings/project_phase_definitions/index_component.html.erb

@@ -77,6 +77,7 @@ See COPYRIGHT and LICENSE files for more details.
             container: "project-phase-definitions",
             position: :relative,
             mb: 3,
+            empty_state_behavior: :dynamic,
             data: drop_target_config
           )
         ) do |list|
@@ -103,11 +104,6 @@ See COPYRIGHT and LICENSE files for more details.
           list.with_empty_state(title: t("settings.project_phase_definitions.non_defined"))
         end
       end
-      flex.with_row(display: :none, data: { "projects--settings--border-box-filter-target": "noResultsText" }) do
-        render Primer::Beta::Text.new do
-          I18n.t("js.autocompleter.notFoundText")
-        end
-      end
     end
   end
 %>