[Layout foundations] Remove Tiles (#7775)

### WHY are these changes introduced?

Resolves #7770.
After discussion among the layout foundations team, we've determined
that `Tiles` does not provide additional benefit that `Column` does not
support. Documentation gets confusing because we are unable to create a
distinction between the two, so we've decided to remove the component
and update guidance on the `Columns` component instead.

### WHAT is this pull request doing?

Removes `Tiles` component and storybook examples.
Removes `Tiles` page from style guide and examples.
Updates `get-props` script in style guide.

### How to 🎩

🖥 [Local development
instructions](https://github.com/Shopify/polaris/blob/main/README.md#local-development)
🗒 [General tophatting
guidelines](https://github.com/Shopify/polaris/blob/main/documentation/Tophatting.md)
📄 [Changelog
guidelines](https://github.com/Shopify/polaris/blob/main/.github/CONTRIBUTING.md#changelog)

### 🎩 checklist

- [ ] Tested on
[mobile](https://github.com/Shopify/polaris/blob/main/documentation/Tophatting.md#cross-browser-testing)
- [ ] Tested on [multiple
browsers](https://help.shopify.com/en/manual/shopify-admin/supported-browsers)
- [ ] Tested for
[accessibility](https://github.com/Shopify/polaris/blob/main/documentation/Accessibility%20testing.md)
- [ ] Updated the component's `README.md` with documentation changes
- [x] [Tophatted
documentation](https://github.com/Shopify/polaris/blob/main/documentation/Tophatting%20documentation.md)
changes in the style guide

Author: laurkim

.changeset/kind-dogs-give.md

@@ -0,0 +1,6 @@
+---
+'@shopify/polaris': minor
+'polaris.shopify.com': minor
+---
+
+Removed `Tiles` and examples in style guide

polaris-react/src/components/Tiles/Tiles.scss

@@ -372,9 +372,6 @@ export type {TextStyleProps} from './components/TextStyle';
 export {Thumbnail} from './components/Thumbnail';
 export type {ThumbnailProps} from './components/Thumbnail';
 
-export {Tiles} from './components/Tiles';
-export type {TilesProps} from './components/Tiles';
-
 export {Toast} from './components/Toast';
 export type {ToastProps} from './components/Toast';