(core) Attempt to fix truncated div issues for menu popups on Safari

Summary:
This affects the "Add Column" submenu under the sort-and-filter dropdown. The
explicit overflow setting (which *should* be the default) seems to fix it.

Test Plan: Tested manually on Safari 17.3 on Mac

Reviewers: georgegevoian

Reviewed By: georgegevoian

Subscribers: jarek, georgegevoian

Differential Revision: https://phab.getgrist.com/D4249

app/client/ui2018/menus.ts

@@ -166,6 +166,7 @@ const cssSubMenuElem = styled('div', `
   min-width: 200px;
 `);
 
+// Note: "overflow: visible" happens to matter for Safari.
 export const cssMenuElem = styled('div', `
   font-family: ${vars.fontFamily};
   font-size: ${vars.mediumFontSize};
@@ -178,6 +179,7 @@ export const cssMenuElem = styled('div', `
   --weaseljs-selected-background-color: ${theme.menuItemSelectedBg};
   --weaseljs-menu-item-padding: 8px 24px;
   background-color: ${theme.menuBg};
+  overflow: visible;
 
   @media print {
     & {