Add explore images icon (#8861)

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### WHY are these changes introduced?

closes: #8862

Adds a new icon to represent the menu action opening free (burst) images
in OSE

<img width="244" alt="New-Icon"
src="https://user-images.githubusercontent.com/103959854/229194990-c575b1de-fdb6-4d3e-bcf0-9e5f8d3a5739.png">

### 🎩 checklist

- [x] Tested on
[mobile](https://github.com/Shopify/polaris/blob/main/documentation/Tophatting.md#cross-browser-testing)
- [x] Tested on [multiple
browsers](https://help.shopify.com/en/manual/shopify-admin/supported-browsers)
- [x] Tested for
[accessibility](https://github.com/Shopify/polaris/blob/main/documentation/Accessibility%20testing.md)
- [x] 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

---------

Co-authored-by: Kyle Durand <kyledurand@users.noreply.github.com>

Author: AlejandroE

.changeset/poor-walls-care.md

@@ -0,0 +1,5 @@
+---
+'@shopify/polaris-icons': minor
+---
+
+Added ExploreImagesMajor

polaris-icons/icons/ExploreImagesMajor.svg

@@ -0,0 +1,11 @@
+name: Explore Images
+set: major
+description: Used to represent exploring a variety of imagery assets
+keywords:
+  - images
+  - media
+authors:
+  - Osama ghazal
+  - Alejandro Echandia
+version: 1
+date_added: 2023-04-05