Fix #111238: Arrow keys in some menus work in the opposite direction

Since menus are created flipped (from event handling point of view), the
root layout block needs to be flagged `UI_BLOCK_IS_FLIP`.
This was missing for a couple of `uiMenuCreateFunc`, namely:
- creating worspaces menu
- modifiers extra ops
- constraints extra ops
- GP modifiers extra ops
- GP Shader FX extra ops

Same fix as f51de2246c.

Not crtitcal, but could go into LTS I guess.

Pull Request: https://projects.blender.org/blender/blender/pulls/111341

source/blender/editors/interface/interface_templates.cc

@@ -2986,6 +2986,8 @@ static void constraint_ops_extra_draw(bContext *C, uiLayout *layout, void *con_v
 
   uiLayoutSetUnitsX(layout, 4.0f);
 
+  UI_block_flag_enable(uiLayoutGetBlock(layout), UI_BLOCK_IS_FLIP);
+
   /* Apply. */
   uiItemO(layout,
           CTX_IFACE_(BLT_I18NCONTEXT_OPERATOR_DEFAULT, "Apply"),

source/blender/editors/screen/workspace_edit.cc

@@ -473,6 +473,8 @@ static void workspace_add_menu(bContext * /*C*/, uiLayout *layout, void *templat
   WorkspaceConfigFileData *startup_config = workspace_config_file_read(app_template);
   WorkspaceConfigFileData *builtin_config = workspace_system_file_read(app_template);
 
+  UI_block_flag_enable(uiLayoutGetBlock(layout), UI_BLOCK_IS_FLIP);
+
   if (startup_config) {
     LISTBASE_FOREACH (WorkSpace *, workspace, &startup_config->workspaces) {
       uiLayout *row = uiLayoutRow(layout, false);

source/blender/gpencil_modifiers_legacy/intern/MOD_gpencil_legacy_ui_common.cc

@@ -240,6 +240,8 @@ static void gpencil_modifier_ops_extra_draw(bContext *C, uiLayout *layout, void
 
   uiLayoutSetUnitsX(layout, 4.0f);
 
+  UI_block_flag_enable(uiLayoutGetBlock(layout), UI_BLOCK_IS_FLIP);
+
   /* Apply. */
   if (!(mti->flags & eGpencilModifierTypeFlag_NoApply)) {
     uiItemO(layout,

source/blender/modifiers/intern/MOD_ui_common.cc

@@ -206,6 +206,8 @@ static void modifier_ops_extra_draw(bContext *C, uiLayout *layout, void *md_v)
 
   uiLayoutSetUnitsX(layout, 4.0f);
 
+  UI_block_flag_enable(uiLayoutGetBlock(layout), UI_BLOCK_IS_FLIP);
+
   /* Apply. */
   uiItemO(layout,
           CTX_IFACE_(BLT_I18NCONTEXT_OPERATOR_DEFAULT, "Apply"),

source/blender/shader_fx/intern/FX_ui_common.cc

@@ -122,6 +122,8 @@ static void gpencil_shaderfx_ops_extra_draw(bContext *C, uiLayout *layout, void
 
   uiLayoutSetUnitsX(layout, 4.0f);
 
+  UI_block_flag_enable(uiLayoutGetBlock(layout), UI_BLOCK_IS_FLIP);
+
   /* Duplicate. */
   uiItemO(layout,
           CTX_IFACE_(BLT_I18NCONTEXT_OPERATOR_DEFAULT, "Duplicate"),