I18n: Extract UI_MENU_ARROW_SEP from translated string

Some places used `IFACE_("For Each Element " UI_MENU_ARROW_SEP "
Main")`, which doesn't work because the arrow separator character is
not extracted by the translation regex. This results instead in:

"For Each Element  Main" (two spaces).

This commit uses string formatting to add the special character after
translation. It's clunky because translators won't see the actual
string, but not as risky right now as trying to include those special
characters in message extraction.

source/blender/nodes/geometry/nodes/node_geo_foreach_geometry_element.cc

@@ -26,6 +26,8 @@
 
 #include "WM_api.hh"
 
+#include "fmt/core.h"
+
 namespace blender::nodes::node_geo_foreach_geometry_element_cc {
 
 /** Shared between zone input and output node. */
@@ -407,22 +409,24 @@ static void node_gather_link_searches(GatherLinkSearchOpParams &params)
   }
   else {
     params.add_item_full_name(
-        IFACE_("For Each Element " UI_MENU_ARROW_SEP " Main"), [](LinkSearchOpParams &params) {
+        fmt::format(IFACE_("For Each Element {} Main"), UI_MENU_ARROW_SEP),
+        [](LinkSearchOpParams &params) {
           const auto [input_node, output_node] = add_foreach_zone(params);
           socket_items::clear<ForeachGeometryElementGenerationItemsAccessor>(*output_node);
           params.update_and_connect_available_socket(*output_node, "Geometry");
         });
 
-    params.add_item_full_name(IFACE_("For Each Element " UI_MENU_ARROW_SEP " Generated"),
-                              [](LinkSearchOpParams &params) {
-                                const auto [input_node, output_node] = add_foreach_zone(params);
-                                params.node_tree.ensure_topology_cache();
-                                bke::node_add_link(params.node_tree,
-                                                   *output_node,
-                                                   output_node->output_socket(2),
-                                                   params.node,
-                                                   params.socket);
-                              });
+    params.add_item_full_name(
+        fmt::format(IFACE_("For Each Element {} Generated"), UI_MENU_ARROW_SEP),
+        [](LinkSearchOpParams &params) {
+          const auto [input_node, output_node] = add_foreach_zone(params);
+          params.node_tree.ensure_topology_cache();
+          bke::node_add_link(params.node_tree,
+                             *output_node,
+                             output_node->output_socket(2),
+                             params.node,
+                             params.socket);
+        });
   }
 }