Add personalized text icon (#8924)

### WHY are these changes introduced?

The email team is currently working on adding the magic-ui component in
order to allow merchants to generate subject lines using the power of
AI. Since the magic icon (green circle) is very similar to the current
icon we use for personalized text (purple circle), we decided to create
a new icon for personalized text.

<img width="1437" alt="Screenshot 2023-04-11 at 9 45 24 PM"
src="https://user-images.githubusercontent.com/3673138/231260362-25f3e097-6852-4526-8ff6-d38637eea280.png">


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### 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)

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  Give as much information as needed to experiment with the component
  in the playground.
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<details>
<summary>Copy-paste this code in
<code>playground/Playground.tsx</code>:</summary>

```jsx
import React from 'react';
import {Page} from '../src';

export function Playground() {
  return (
    <Page title="Playground">
      {/* Add the code you want to test in here */}
    </Page>
  );
}
```

</details>

### 🎩 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
- [ ] [Tophatted
documentation](https://github.com/Shopify/polaris/blob/main/documentation/Tophatting%20documentation.md)
changes in the style guide

---------

Co-authored-by: Kyle Durand <[email protected]>

Author: talbshoam

.changeset/moody-timers-build.md

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

polaris-icons/icons/PersonalizedTextMajor.svg

@@ -0,0 +1,15 @@
+name: Personalized text
+set: major
+description: Used to represent personalized text features.
+keywords:
+  - Personalized text
+  - Personalization
+  - Customer attributes
+  - Customer
+  - Dynamic content
+authors:
+  - Natalie Hercun
+version: 1
+date_added: 2023-04-11
+date_modified: 2023-04-11
+exclusive_use: For use related to feature using personalized text