Config: Refactor frontend settings to struct (#61990)

* Config: Make frontend settings a struct rather than map

remove frontend settings to setting package

remove frontend settings struct to dtos package

rearrange structs to avoid cycles

rename getFrontendSettings fn

omitempty

fix login test

fix middleware test

* wip some enterprise types

* cleanup, moved structs from enterprise

* ci

pkg/middleware/middleware_test.go

@@ -167,7 +167,7 @@ func TestMiddlewareContext(t *testing.T) {
 			t.Log("Handler called")
 			data := &dtos.IndexViewData{
 				User:     &dtos.CurrentUser{},
-				Settings: map[string]interface{}{},
+				Settings: &dtos.FrontendSettingsDTO{},
 				NavTree:  &navtree.NavTreeRoot{},
 			}
 			t.Log("Calling HTML", "data", data)