Conform more of the codebase to strictNullChecks (#10350

* Conform more of the codebase to `strictNullChecks`

* Iterate

* Generics ftw

* Iterate

src/accessibility/context_menu/ContextMenuButton.tsx

@@ -39,7 +39,7 @@ export const ContextMenuButton: React.FC<IProps> = ({
         <AccessibleButton
             {...props}
             onClick={onClick}
-            onContextMenu={onContextMenu || onClick}
+            onContextMenu={onContextMenu ?? onClick ?? undefined}
             title={label}
             aria-label={label}
             aria-haspopup={true}

src/accessibility/context_menu/ContextMenuTooltipButton.tsx

@@ -37,7 +37,7 @@ export const ContextMenuTooltipButton: React.FC<IProps> = ({
         <AccessibleTooltipButton
             {...props}
             onClick={onClick}
-            onContextMenu={onContextMenu || onClick}
+            onContextMenu={onContextMenu ?? onClick ?? undefined}
             aria-haspopup={true}
             aria-expanded={isExpanded}
             forceHide={isExpanded}