refactor(item-sliding): remove unused CSS from item options (#28367)

Issue number: Internal

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## What is the current behavior?
Item sliding has some unused CSS and no tests for safe area padding
based on the direction.

This CSS is not used:
https://github.com/ionic-team/ionic-framework/blob/feda7a0e963048d300eb17d4b9e1056f09088714/core/src/components/item-option/item-option.scss#L20-L30

The rendered markup for a sliding item looks like the following:

```html
<ion-item-sliding>
  <ion-item-options side="start">
    <ion-item-option>
      Archive
    </ion-item-option>
  </ion-item-options>

  <ion-item class="in-list">
    <ion-label>
      Sliding Item
    </ion-label>
  </ion-item>
</ion-item-sliding>
```

Since `ion-item-options` never gets the `in-list` class added to it, and
`ion-item` never contains options, the above CSS is never used.

## What is the new behavior?
<!-- Please describe the behavior or changes that are being added by
this PR. -->

- Removed the CSS that is not used, the correct CSS for safe area
padding has already been added here:
https://github.com/ionic-team/ionic-framework/blob/feda7a0e963048d300eb17d4b9e1056f09088714/core/src/components/item-options/item-options.scss#L57-L67
- Added screenshot tests to verify the safe area padding is applied to
the proper side

## Does this introduce a breaking change?

- [ ] Yes
- [x] No

## Other information

I could add additional tests that make sure there is not padding added
when opening the opposite side on each direction but since this problem
was happening when changing from `ltr` to `rtl` I did not.

[FW-5174]:
https://ionic-cloud.atlassian.net/browse/FW-5174?atlOrigin=eyJpIjoiNWRkNTljNzYxNjVmNDY3MDlhMDU5Y2ZhYzA5YTRkZjUiLCJwIjoiZ2l0aHViLWNvbS1KU1cifQ

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Co-authored-by: ionitron <hi@ionicframework.com>