Fix vertical spacing in compact <ContextMenu> (#7684)

Fix https://github.com/vector-im/element-web/issues/20801

Regressed in https://github.com/matrix-org/matrix-react-sdk/pull/7339

Relevant styles were first added in https://github.com/matrix-org/matrix-react-sdk/pull/4858
(context behind why the original styles were added)

---

## Cause

Battling CSS specificity between the default and compact styles, https://specificity.keegan.st/

Known good (On `app.element.io` (expected)):
```css
// 0 3 0
.mx_IconizedContextMenu .mx_IconizedContextMenu_optionList .mx_AccessibleButton {
    padding-top: 12px;
    padding-bottom: 12px;
}

// Compact styles override our default rules because they come
// after the other styles (source order) and have the same specificity
// 0 3 0
.mx_IconizedContextMenu.mx_IconizedContextMenu_compact .mx_IconizedContextMenu_optionList > * {
    padding: 8px 16px 8px 11px;
}
```

Bad (On `develop` (broken)):
```css
// Default rules always override because they have higher specificity.
// The `:not()` selector doesn't add any extra specificity but the selectors inside the `:not(...)` do.
// 0 4 0
.mx_IconizedContextMenu .mx_IconizedContextMenu_optionList .mx_AccessibleButton:not(.mx_AccessibleButton_hasKind) {
    padding-top: 12px;
    padding-bottom: 12px;
}

// 0 3 0
.mx_IconizedContextMenu.mx_IconizedContextMenu_compact .mx_IconizedContextMenu_optionList > * {
    padding: 8px 16px 8px 11px;
}
```

res/css/views/messages/_JumpToDatePicker.scss

@@ -16,6 +16,10 @@ limitations under the License.
 
 .mx_JumpToDatePicker_form {
     display: flex;
+    // This matches the default padding of IconizedContextMenuOption
+    // (see context_menus/_IconizedContextMenu.scss)
+    padding-top: 12px;
+    padding-bottom: 12px;
 }
 
 .mx_JumpToDatePicker_label {