Add aria-label to filter panel close button

The desktop "close filters" button in the search results filter panel
was an icon-only IconButton with no accessible name. A screen reader
announced it only as "button", so users could not tell what it does.

Add aria-label="Close filters", matching the pattern already used by the
sibling "Clear organization name filter" button in the same file and the
"close" button in AnnouncementSnackbar.

Also add a Playwright test that opens the filter panel, asserts the close
button is reachable by its accessible name, and confirms it closes the panel.

Author: olitreadwell

client/src/components/FoodSeeker/SearchResults/ResultsFilters/FilterPanel.tsx

@@ -152,7 +152,7 @@ const FilterPanel: FC<FilterPanelProps> = ({ mealPantry, filterCount }) => {
             {`${filterCount} ${filterCount === 1 ? "Location" : "Locations"}`}
           </Typography>
           {isDesktop ? (
-            <IconButton onClick={handleDrawerClose}>
+            <IconButton aria-label="Close filters" onClick={handleDrawerClose}>
               <CloseIcon />
             </IconButton>
           ) : (

client/tests/organizations.spec.ts

@@ -108,4 +108,18 @@ test.describe("Organizations", () => {
     await expect(page.getByText("Stakeholder 2")).toBeVisible();
     await expect(page.getByText("Stakeholder 3")).toBeHidden();
   });
+
+  test("filter panel close button has an accessible name and closes the panel", async ({
+    page,
+  }) => {
+    await mockRequests(page);
+    await page.goto("/organizations");
+    await page.getByRole("button", { name: "More Filters" }).click();
+
+    const closeFilters = page.getByRole("button", { name: "Close filters" });
+    await expect(closeFilters).toBeVisible();
+
+    await closeFilters.click();
+    await expect(closeFilters).toBeHidden();
+  });
 });